# Configuration

Configuration and customization of Sphinx-Gallery is done primarily with a dictionary specified in your `conf.py` file. A list of the possible keys are listed below and explained in greater detail in subsequent sections.

When using these flags, it is good practice to make sure the source Python files are equivalent to the generated HTML and iPython notebooks (i.e. make sure `.py == .html == .ipynb`). This principle should be violated only when necessary, and on a case-by-case basis.

## Configuration options

### Global `conf.py` configurations

Sphinx-Gallery configuration options that can be set in the Sphinx `conf.py` file, inside a `sphinx_gallery_conf` dictionary.

Gallery files and ordering

- `examples_dirs` and `gallery_dirs` (Manage multiple galleries)

- `filename_pattern`, `ignore_pattern`, `example_extensions`, and `filetype_parsers` (Parsing and executing examples via matching patterns)

- `copyfile_regex` (Manually passing files)

- `subsection_order` (Sorting gallery subsections)

- `within_subsection_order` (Sorting gallery examples)

- `nested_sections` (Nesting gallery sections)

Example execution

- `reset_argv` (Passing command line arguments to example scripts)

- `capture_repr` and `ignore_repr_types` (Controlling what output is captured)

- `plot_gallery` (Building without executing examples)

- `run_stale_examples` (Rerunning stale examples)

- `abort_on_example_error` (Abort build on first fail)

- `expected_failing_examples` (Don’t fail the build if specific examples error)

- `only_warn_on_example_error` (Never fail the build on error)

- `reset_modules` and `reset_modules_order` (Resetting modules)

- `parallel` (Build examples in parallel)

Diverging from Jupyter

Sphinx-gallery attempts to render examples to HTML in a manner largely consistent with what a user will experience when they download the corresponding `.ipynb` notebook file and run it locally. Some options, such as `'capture_repr': (),`, will make these behaviors less consistent. Consider using these options sparingly as it could lead to confusion or sub-optimal experiences for users!

Cross-referencing

- `reference_url`, `prefer_full_module` (Add intersphinx links to your examples)

- `backreferences_dir`, `doc_module`, `exclude_implicit_doc`, and `inspect_global_variables` (Add mini-galleries)

- `minigallery_sort_order` (Sort mini-gallery thumbnails from files)

Images and thumbnails

- `default_thumb_file` (Using a custom default thumbnail)

- `thumbnail_size` (Setting gallery thumbnail size)

- `image_srcset` (Multi-resolution images)

- `image_scrapers` (Image scrapers)

- `compress_images` (Compressing images)

Compute costs

- `min_reported_time` (Minimal reported time)

- `write_computation_times` (Write computation times)

- `show_memory` (Showing memory consumption)

- `junit` (Using JUnit XML files)

Jupyter notebooks and interactivity

- `notebook_extensions` (Controlling notebook download links)

- `promote_jupyter_magic` (Making cell magic executable in notebooks)

- `first_notebook_cell` and `last_notebook_cell` (Add your own first and last notebook cell)

- `notebook_images` (Adding images to notebooks)

- `pypandoc` (Using pypandoc to convert reST to markdown)

- `binder` (Generate Binder links for gallery notebooks (experimental))

- `jupyterlite` (Generate JupyterLite links for gallery notebooks (experimental))

Appearance

- `line_numbers` (Adding line numbers to examples)

- `remove_config_comments` (Removing config comments)

- `show_signature` (Show signature)

- `download_all_examples` (Disabling download button of all scripts)

Miscellaneous

- `recommender` (Enabling the example recommender system)

- `log_level` (Setting log level)

- `show_api_usage` and `api_usage_ignore` (Showing API Usage)

### Configurations inside examples

Some options can also be set or overridden on a file-by-file basis:

- `# sphinx_gallery_line_numbers` (Adding line numbers to examples)

- `# sphinx_gallery_thumbnail_number` (Choosing the thumbnail image)

- `# sphinx_gallery_thumbnail_path` (Providing an image for the thumbnail image)

- `# sphinx_gallery_failing_thumbnail` (Controlling thumbnail behaviour in failing examples)

- `# sphinx_gallery_dummy_images` (Generating dummy images)

- `# sphinx_gallery_capture_repr` (Controlling what output is captured)

- `# sphinx_gallery_multi_image` (Controlling the layout of multiple figures from the same code block)

Some options can be set on a per-code-block basis in a file:

- `# sphinx_gallery_capture_repr_block` (Controlling what output is captured)

- `# sphinx_gallery_defer_figures` (Using multiple code blocks to create a single figure)

- `# sphinx_gallery_multi_image_block` (Controlling the layout of multiple figures from the same code block)

Some options can be set on a per-line basis in a file: - `# sphinx_gallery_start_ignore` and `# sphinx_gallery_end_ignore` (Hiding lines of code)

See also Removing config comments to hide config comments in files from the rendered examples.

### Build options

Some options can be set during the build execution step, e.g. using a Makefile:

- `make html-noplot` (Building without executing examples)

- `make html_abort_on_example_error` (Abort build on first fail)

### CSS changes

Some things can be tweaked directly in CSS:

- `.sphx-glr-thumbcontainer` (Setting gallery thumbnail size)

## Removing warnings

To prevent warnings from being captured and included in your built documentation, you can use the package `warnings` in the `conf.py` file. For example, to remove the specific Matplotlib agg warning, you can add:

    import warnings

    warnings.filterwarnings("ignore", category=UserWarning,
                            message='Matplotlib is currently using agg, which is a'
                                    ' non-GUI backend, so cannot show the figure.'
                                    '|(\n|.)*is non-interactive, and thus cannot be shown')

to your `conf.py` file.

Note that the above Matplotlib warning is removed by default.

## Importing callables

Sphinx-Gallery configuration values that are instantiated classes, classes or functions should be passed as fully qualified name strings to the objects. The object needs to be importable by Sphinx-Gallery.

Two common ways to achieve this are:

1. Define your object with your package. For example, you could write a function `def my_sorter` and put it in `mymod/utils.py`, then use:

       sphinx_gallery_conf = {
       #...,
       "minigallery_sort_order": "mymod.utils.my_sorter",
       #...
       }

2. Define your object with your documentation. For example, you can add documentation-specific stuff in a different path and ensure that it can be resolved at build time. For example, you could create a file `doc/sphinxext.py` and define your function:

       def plotted_sorter(fname):
           return not fname.startswith("plot_"), fname

   And set in your configuration:

       sys.path.insert(0, os.path.dirname(__file__))

       sphinx_gallery_conf = {
       #...,
       "minigallery_sort_order": "sphinxext.plotted_sorter",
       #...
       }

   And Sphinx-Gallery would resolve `"sphinxext.plotted_sorter"` to the `plotted_sorter` object because the `doc/` directory is first on the path.

Built in classes like `sphinx_gallery.sorting.FileNameSortKey` and similar can be used with shorter direct alias strings like `"FileNameSortKey"` (see Sorting gallery examples for details).

Note

Sphinx-Gallery >0.16.0 supports use of fully qualified name strings as a response to the Sphinx >7.3.0 changes to caching and serialization checks of the `conf.py` file.

This means that the previous use of class instances as configuration values to ensure the `__repr__` was stable across builds is redundant if you are passing configuration values via name strings. When using name strings, the configuration object can just be a function.

## Custom sort keys

You can create a custom sort key callable for the following configurations:

- subsection_order - to reorder subsections (sub-galleries) (passed subsection folder paths relative to the `conf.py` file)

- within_subsection_order - to reorder gallery items within (sub)sections (passed filenames)

- minigallery_sort_order - to reorder minigallery items (passed full paths to example files and backreference files)

The best way to do this is to define a sort function, that takes the passed path string. For example, this function puts all filenames starting with `plot_` before all other filenames:

    def plotted_sorter(fname):
        return (not fname.startswith("plot_"), fname)

Then make sure it is importable (see Importing callables) and set your configuration:

    sphinx_gallery_conf = {
    #...,
    "minigallery_sort_order": "sphinxext.plotted_sorter",
    #...
    }

For backwards compatibility you can also set your configuration to be a callable object but you will have to ensure that the `__repr__` is stable across runs. See Ensuring a stable __repr__ for details.

If you do this, we recommend that you use the `sphinx_gallery.sorting.FunctionSortKey` because it will ensure that the `__repr__` is stable across runs.

`sphinx_gallery.sorting.FunctionSortKey` takes a function on init. You can create your sort key callable by instantiating a `FunctionSortKey` instance with your sort key function. For example, the following `minigallery_sort_order` configuration (which sorts on paths) will sort using the first 10 letters of each filename:

    sphinx_gallery_conf = {
    #...,
    "minigallery_sort_order": FunctionSortKey(
        lambda filename: filename[:10]),
    #...
    }

## Ensuring a stable `__repr__`

For backwards compatibility Sphinx-Gallery allows certain configuration values to be a callable object instead of a importable name string.

If you wish to use a callable object you will have to ensure that the `__repr__` is stable across runs. Sphinx determines if the build environment has changed, and thus if all documents should be rewritten, by examining the config values using `md5(str(obj).encode()).hexdigest()` in `sphinx/builders/html.py`. Default class instances in Python have their memory address in their `__repr__` which is why generally the `__repr__` changes in each build.

Your callable should be a class that defines a stable `__repr__` method. For example, `sphinx_gallery.sorting.ExplicitOrder` stability is ensured via the custom `__repr__`:

    def __repr__(self):
        return '<%s: %s>' % (self.__class__.__name__, self.ordered_list)

Therefore, the files are only all rebuilt when the specified ordered list is changed.

## Manage multiple galleries

To specify the locations of your input and output gallery folder(s), use the following Sphinx-Gallery configuration dictionary keys:

- `examples_dirs` (folder where source example files are)

- `gallery_dirs` (folder where output files should be placed)

Both configurations take list of directory paths, relative to the `conf.py` file. They can be set in your Sphinx `conf.py` file:

    sphinx_gallery_conf = {
        ...
        'examples_dirs': ['../examples', '../tutorials'],
        'gallery_dirs': ['auto_examples', 'tutorials'],
    }

Keep in mind that both lists should be of the same length.

Each folder in `examples_dirs` will be built into an examples gallery. Subfolders within each `examples_dirs` will be built into gallery subsections (sub-galleries) of the parent gallery.

Sphinx-Gallery only supports one level of subfolder nesting in its gallery directories. For example our Basics Gallery with Matplotlib, has the parent gallery in examples/ and the subsection (aka sub-gallery) in examples/no_output/. Further sub-folders are not supported. This might be a limitation for you, or you might want to have separate galleries for different purposes, e.g., an examples gallery and a tutorials gallery.

Note

If your examples take a long time to run, consider looking at the execution times file that is generated for each gallery dir (as long as any examples were actually executed in that directory during the build) and globally for all galleries.

## Parsing and executing examples via matching patterns

By default, Sphinx-Gallery will parse and add all files with a `.py` extension to the gallery, but only execute files beginning with `plot_`. These behaviors are controlled by the `ignore_pattern`, `filename_pattern`, and `example_extensions` entries, which have the default values:

    sphinx_gallery_conf = {
        ...
        'filename_pattern': '/plot_',
        'ignore_pattern': r'__init__\.py',
        'example_extensions': {'.py'}
    }

To omit some files from the gallery entirely (i.e., not execute, parse, or add them), you can change the `ignore_pattern` option. To choose which of the parsed and added Python scripts are actually executed, you can modify `filename_pattern`. For example:

    sphinx_gallery_conf = {
        ...
        'filename_pattern': '/plot_compute_',
    }

will build all examples starting with `plot_compute_`. The key `filename_pattern` (and `ignore_pattern`) accepts regular expressions which will be matched with the full path of the example. This is the reason the leading `'/'` is required. Users are advised to use `re.escape(os.sep)` instead of `'/'` if they want to be agnostic to the operating system.

The `filename_pattern` option is also useful if you want to build only a subset of the examples. For example, you may want to build only one example so that you can link it in the documentation. In that case, you would do:

    sphinx_gallery_conf = {
        ...
        'filename_pattern': r'plot_awesome_example\.py',
    }

Here, one should escape the dot `r'\.'` as otherwise python regular expressions matches any character. Nevertheless, as one is targeting a specific file, it would match the dot in the filename even without this escape character.

Note

Sphinx-Gallery only re-runs examples that have changed (according to their md5 hash). See Rerunning stale examples below for information.

Similarly, to build only examples in a specific directory, you can do:

    sphinx_gallery_conf = {
        ...
        'filename_pattern': '/directory/plot_',
    }

Alternatively, you can skip executing some examples. For example, to skip building examples starting with `plot_long_examples_`, you would do:

    sphinx_gallery_conf = {
        ...
        'filename_pattern': '/plot_(?!long_examples)',
    }

As the patterns are parsed as regular expressions, users are advised to consult the regular expressions module for more details.

Note

Remember that Sphinx allows overriding `conf.py` values from the command line, so you can for example build a single example directly via something like:

    $ sphinx-build -D sphinx_gallery_conf.filename_pattern=plot_specific_example\.py ...

You can also parse and highlight syntax examples in other languages by adding their extensions to `example_extensions`, though they will not be executed. For example, to include examples in Python, Julia, and C++:

    sphinx_gallery_conf = {
        ...
        'example_extensions': {'.py', '.jl', '.cpp'}
    }

Parsing and syntax highlighting is supported by the Pygments library, with the language determined by the file extension. To override Pygments’ default file associations, the `filetype_parsers` option can be used to specify a `dict` mapping any of the file extensions in `example_extensions` to any of the pygments language names. For example:

    sphinx_gallery_conf = {
        ...
        'filetype_parsers': {'.m': 'Matlab'}
    }

## Rerunning stale examples

By default, Sphinx-Gallery only rebuilds examples that have changed. For example, when starting from a clean `doc/` directory, running your HTML build once will result in Sphinx-Gallery executing all examples that match your given filename/ignore patterns. Then, running the exact same command a second time should not run any examples, because the MD5 hash of each example will be checked against the MD5 hash (saved to disk as `<filename>.md5` in the generated directory) that the example file had during the first build. These will match and thus the example will be determined to be “stale”, and it will not be rebuilt by Sphinx-Gallery. This design feature allows for more rapid documentation iteration by only rebuilding examples when they change.

However, this presents a problem during some modes of debugging and iteration. Let’s say that you have one particular example that you want to rebuild repeatedly while modifying some function in your underlying library but do not want to change the example file contents themselves. To do this, you’d either need to make some change (e.g., add/delete a newline) to your example or delete the `.md5` file to force Sphinx-Gallery to rebuild the example. Instead, you can use the configuration value:

    sphinx_gallery_conf = = {
        ...
        'run_stale_examples': True,
    }

With this configuration, all examples matching the filename/ignore pattern will be rebuilt, even if their MD5 hash shows that the example did not change. You can combine this with filename/ignore patterns to repeatedly rerun a single example. This could be done from the command line, for example:

    $ make html SPHINXOPTS="-D sphinx_gallery_conf.run_stale_examples=True -D sphinx_gallery_conf.filename_pattern='my_example_name'"

This command will cause any examples matching the filename pattern `'my_example_name'` to be rebuilt, regardless of their MD5 hashes.

## Passing command line arguments to example scripts

By default, Sphinx-Gallery will not pass any command line arguments to example scripts. By setting the `reset_argv` option, it is possible to change this behavior and pass command line arguments to example scripts. `reset_argv` needs to be a `Callable` that accepts the `gallery_conf` and `script_vars` dictionaries as input and returns a list of strings that are passed as additional command line arguments to the interpreter.

A `reset_argv` example could be:

    from pathlib import Path

    def reset_argv(sphinx_gallery_conf, script_vars):
        src_file = Path(script_vars['src_file']).name
        if src_file == 'example1.py':
            return ['-a', '1']
        elif src_file == 'example2.py':
            return ['-a', '2']
        else:
            return []

This function is defined in `doc/sphinxext.py` and we ensured that it is importable (see Importing callables).

This can be included in the configuration dictionary as:

    sphinx_gallery_conf = {
        ...
        'reset_argv': "sphinxext.reset_argv",
    }

which is then resolved by Sphinx-Gallery to the callable `reset_argv` and used as:

    import sys
    sys.argv[0] = script_vars['src_file']
    sys.argv[1:] = reset_argv(gallery_conf, script_vars)

Note

For backwards compatibility you can also set your configuration to be a callable object but you will have to ensure that the `__repr__` is stable across runs. See Ensuring a stable __repr__.

## Sorting gallery subsections

Gallery subsections (aka sub-galleries) are sorted by default alphabetically by their folder name, and as such you can always organize them by changing your folder names. Alternatively, you can specify the order via the config value `subsection_order` by providing a list of the subsections as paths relative to `conf.py` in the desired order:

    sphinx_gallery_conf = {
        ...
        'examples_dirs': ['../examples','../tutorials'],
        'subsection_order': ['../examples/sin_func',
                             '../examples/no_output',
                             '../tutorials/seaborn'],
    }

Here we build 2 main galleries examples and tutorials, each of them with subsections. You must list all subsections. If that’s too cumbersome, one entry can be “*”, which will collect all not-listed subsections, e.g. `["first_subsection", "*", "last_subsection"]`.

Even more generally, you can set `subsection_order` to any callable, which will be used as the sorting key function on the subsection folder paths (relative to the `conf.py` file). See Custom sort keys for more information.

In fact, the above list is a convenience shortcut and it is internally wrapped in `sphinx_gallery.sorting.ExplicitOrder` as a sortkey.

Note

Sphinx-Gallery <0.16.0 required to wrap the list in `ExplicitOrder`

    from sphinx_gallery.sorting import ExplicitOrder
    sphinx_gallery_conf = {
        ...
        'subsection_order': ExplicitOrder([...])
    }

This pattern is discouraged in favor of passing the simple list.

Keep in mind that we use a single sort key for all the galleries that are built, thus we include the prefix of each gallery in the corresponding subsection folders. One does not define a sortkey per gallery. You can use Linux paths, and if your documentation is built in a Windows system, paths will be transformed to work accordingly, the converse does not hold.

## Sorting gallery examples

Within a given gallery (sub)section, the example files are ordered by using the standard `sorted()` function with the `key` argument by default set to `NumberOfCodeLinesSortKey(src_dir)`, which sorts the files based on the number of code lines:

    sphinx_gallery_conf = {
        ...
        'within_subsection_order': "NumberOfCodeLinesSortKey",
    }

Built in convenience classes supported by `within_subsection_order`:

- `sphinx_gallery.sorting.NumberOfCodeLinesSortKey` (default) to sort by the number of code lines.

- `sphinx_gallery.sorting.FileSizeSortKey` to sort by file size.

- `sphinx_gallery.sorting.FileNameSortKey` to sort by file name.

- `sphinx_gallery.sorting.ExampleTitleSortKey` to sort by example title.

These built in Sphinx-Gallery classes can be specified using just the classname as a string, e.g., `"FileSizeSortKey"`. It is functionally equivalent to providing the fully qualified name string `"sphinx_gallery.sorting.NumberOfCodeLinesSortKey"` or importing and passing the class. See Importing callables for details.

You can also pass your own custom sort key callable, which will be used to sort the full paths to example files in the (sub)section. See Custom sort keys for more information.

Note

For backwards compatibility, `within_subsection_order` can also be a class, which will be instantiated with the full path to the output directory; gallery_dir.

## Add intersphinx links to your examples

Sphinx-Gallery enables you to add hyperlinks to the code blocks in your example files. This links functions/methods/attributes/objects/classes used, to their matching online documentation.

Such code snippets within the gallery appear like this:

    y = np.sin(x)

Note

Sphinx-Gallery does not manage hyperlinks in reST text blocks. These depend on your Sphinx setup. If your project uses `sphinx.ext.intersphinx`, hyperlinks to external modules will be added to text blocks, similar to a normal Sphinx reST documentation file.

If you use the Sphinx extension `sphinx.ext.intersphinx`, entries in the `intersphinx` inventory will automatically be used for linking inside code blocks. If you wish to add or over-ride any `intersphinx` module, you can use the Sphinx-Gallery `reference_url` configuration. `reference_url` accepts a dictionary where the key is the module name string and value is the URL to the module’s documentation directory page, containing `searchindex.js`, such as `'matplotlib': 'https://matplotlib.org'`.

To link the local module, use `None` as the value, as shown below:

    sphinx_gallery_conf = {
        ...
        'reference_url': {
             # The module you locally document uses None
            'sphinx_gallery': None,
        }
    }

To add links to code blocks in plain reST example files inside galleries, see Plain reST examples.

Have a look at this functionality in full action in our example Introductory example - Plotting sin.

### Resolving module paths

When finding links to objects we use, by default, the shortest module path, checking that it still directs to the same object. This is because it is common for a class that is defined in a deeper module to be documented in a shallower one because it is imported in a higher level modules’ `__init__.py` (thus that’s the namespace users expect it to be).

However, if you are using inherited classes in your code and are experiencing incorrect links in the sense that links point to the base class of an object instead of the child, the option `prefer_full_module` might solve your issue. See the GitHub issue for more context.

To make this work in your documentation you need to include `prefer_full_module` in the Sphinx-Gallery configuration dictionary in `conf.py`:

    sphinx_gallery_conf = {
        ...
        # Regexes to match the fully qualified names of objects where the full
        # module name should be used. To use full names for all objects use: '.*'
        'prefer_full_module': {r'module\.submodule'}
    }

In the above example, all fully qualified names matching the regex `'module\.submodule'` would use the full module name (e.g., module.submodule.meth) when creating links, instead of the short module name (e.g., module.meth). All others will use the (default) way of linking.

## Add mini-galleries

Sphinx-Gallery provides the `sphinx_gallery.directives.MiniGallery` directive so that you can easily add a gallery of specific examples, a ‘mini-gallery’, to your reST. This directive works in both reST text blocks in examples and `.rst` files.

The minigallery directive supports passing a list, as a space separated directive argument or in the body of the directive. There are two ways to specify examples to include in the mini-gallery:

- via fully qualified names of object (see Add mini-galleries for API documentation) - this adds all examples where the object was used in the code or referenced in the example text

- via pathlike strings to example Python files, including glob-style (see Create mini-galleries using file paths)

To use object names, you must enable backreference generation, see Add mini-galleries for API documentation for details. If backreference generation is not enabled, object entries to the `MiniGallery` directive will be ignored and all entries will be treated as pathlike strings or glob-style pathlike strings. See Create mini-galleries using file paths for details.

For example, the reST below will add a mini-gallery that includes all examples that use or reference the specific function `numpy.exp`, the example `examples/plot_sin_.py`, and all example files matching the string `/examples/plot_4*`:

    .. minigallery:: numpy.exp ../examples/plot_0_sin.py ../examples/plot_4*

All relevant examples will be merged into a single mini-gallery. The mini-gallery will only be shown if the files exist or the items are actually used or referred to in an example. Sphinx-Gallery will prevent duplication, ensuring that examples ‘passed’ more than once (e.g., one example uses a passed object and matches a passed file string) will only appear once in the mini-gallery.

You can also sort the examples in your mini-galleries. See Sort mini-gallery thumbnails from files for details.

The mini-gallery directive also supports the following options:

- `add-heading` - adds a heading to the mini-gallery.

  - The default heading for a mini-gallery with a single passed argument is: “Examples using {full qualified object name}”.

  - The default heading for a mini-gallery with multiple passed arguments is: “Examples of one of multiple objects”.

- `heading-level` - specify the heading level. Accepts a single character (e.g., `-`).

For example, the following reST adds the heading “My examples”, with heading level `-`. It also shows how to pass inputs in the body of the directive (instead of as directive arguments).

    .. minigallery::
        :add-heading: My examples
        :heading-level: -

        numpy.exp
        ../examples/plot_0_sin.py
        ../examples/plot_4*

### Add mini-galleries for API documentation

Sphinx-Gallery can generate minigalleries for objects from specified modules, consisting of all examples that either:

1. Use the function/method/attribute/object or instantiate the class in the code (called implicit backreferences) or

2. Refer to that function/method/attribute/object/class using sphinx markup `:func:` / `:meth:` / `:attr:` / `:obj:` / `:class:` in a text block. You can omit this role markup if you have set the default_role in your `conf.py` to any of these roles (called explicit backreferences).

This allows you to pass a fully qualified name of an object (e.g., function, method, attribute, class) to the minigallery directive to add a minigallery of all examples relevant to that object. This can be useful in API documentation.

Implicit backreferences are useful for auto-documenting objects that are used and classes that are explicitly instantiated, in the code. Any examples where an object is used in the code are added implicitly as backreferences.

Explicit backreferences are for objects that are explicitly referred to in an example’s text. They are useful for classes that are typically implicitly returned in the code rather than explicitly instantiated (e.g., `matplotlib.axes.Axes` which is most often instantiated only indirectly within function calls).

For example, we can embed a small gallery of all examples that use or refer to `numpy.exp`, which looks like this:

### Examples using `numpy.exp`

Plotting the exponential function

Plotting the exponential function

Choosing the thumbnail figure

Choosing the thumbnail figure

Identifying function names in a script

Identifying function names in a script

For such behavior to be available, set the following Sphinx-Gallery configurations in your `conf.py` file:

Required

- `backreferences_dir` - directory where object granular galleries are stored.

  - This should be a string or `pathlib.Path` object that is relative to the `conf.py` file, or `None`.

  - It is `None` by default, which means that backrefererences are not generated.

- `doc_module` - the modules for which you want object level galleries to be created.

  - It should be a tuple of string module names.

Optional

- `exclude_implicit_doc` - Regexes to match objects to exclude from implicit backreferences, as set of string regexes.

  - The default option is an empty set, which will exclude nothing.

  - See exclude_implicit_doc for details.

For example:

    sphinx_gallery_conf = {
        ...
        # directory where function/class granular galleries are stored
        'backreferences_dir'  : 'gen_modules/backreferences',

        # here we want to create backreferences for sphinx_gallery and numpy
        'doc_module'          : ('sphinx_gallery', 'numpy'),

        # Regexes to match objects to exclude from implicit backreferences.
        'exclude_implicit_doc': {r'pyplot\.show'},
    }

The path you specify in `backreferences_dir` (here we choose `gen_modules/backreferences`) will be populated with a file called “backreferences_all.json”. This contains a mapping of all of all objects belonging to the modules listed in `doc_module` and not excluded in `exclude_implicit_doc`, to the examples where it was used or referenced. Objects not used or referenced in any example are not included.

For backwards compatibility `backreferences_dir` will also be populated with reST files for each object, named ‘<object>.examples’. Each .rst file will contain a reduced version of the gallery, containing examples where that “object” that is used. ‘<object>.examples’ files will be generated for all objects to prevent inclusion errors. Empty ‘<object>.examples’ files are created for objects not used in any example.

#### `exclude_implicit_doc`

Sometimes, there are functions that are being used in practically every example for the given module, for instance the `pyplot.show` or `pyplot.subplots` functions in Matplotlib, so that a large number of often spurious examples will be linked to these functions. To prevent this, you can exclude implicit backreferences for certain objects by including them as regular expressions in `exclude_implicit_doc`. The following setting will exclude any implicit backreferences so that examples galleries are only created for objects explicitly mentioned by Sphinx markup in a documentation block: `{'.*'}`. To exclude the functions mentioned above you would use `{r'pyplot\.show', r'pyplot\.subplots'}` (note the escape to match a dot instead of any character, if the name is unambiguous you can also write `pyplot.show` or just `show`).

### Create mini-galleries using file paths

Sometimes you may want to explicitly create a `mini-gallery` using files that do not have functions in common, for example a set of tutorials. The mini-gallery directive therefore also supports passing in:

- pathlike strings to sphinx gallery example files (relative to `conf.py`)

- glob-style pathlike strings to Sphinx-Gallery example files (relative to `conf.py`). For example, passing `/examples/plot_4*` will include all example files matching the above pattern.

#### Sort mini-gallery thumbnails from files

The minigallery directive generates a gallery of thumbnails corresponding to the input file strings or object names. You can specify minigallery thumbnails order via the `minigallery_sort_order` configuration, which gets passed to the `sorted()` `key` parameter when sorting all minigalleries.

Sorting is done on the full paths to all the gallery examples (e.g., `path/to/plot_example.py`) that correspond to the inputs.

See Custom sort keys for details on writing a custom sort key.

For example, to put all example thumbnails starting with `"plot_numpy_"` at the start, we could define the function below in `doc/sphinxext.py` (note `False` gets sorted ahead of `True` as 0 is less than 1):

    def function_sorter(x)
        return (not Path(x).name.starts_with("plot_numpy_"), x)::

We can then set the configuration to be (ensuring the function is importable):

    sphinx_gallery_conf = {
        #...,
        "minigallery_sort_order": "sphinxext.function_sorter",
        #...
    }

Sphinx-Gallery would resolve `"sphinxext.function_sorter"` to the `function_sorter` object.

Note that you can only define one sorting key for all minigalleries.

### Auto-documenting your API with links to examples

The previous feature can be automated for all your modules combining it with the standard sphinx extensions autodoc and autosummary. First enable them in your `conf.py` extensions list:

    import sphinx_gallery
    extensions = [
        ...
        'sphinx.ext.autodoc',
        'sphinx.ext.autosummary',
        'sphinx_gallery.gen_gallery',
        ]

    # generate autosummary even if no references
    autosummary_generate = True

autodoc and autosummary are very powerful extensions, please read about them. In this example we’ll explain how the Sphinx-Gallery API Reference is automatically generated. The documentation is done at the module level. We first start with the `reference.rst` file

    .. _sphx_glr_api_reference:

    Sphinx-Gallery API Reference
    ============================

    .. note::
       Sphinx-Gallery is typically used indirectly via Sphinx execution and
       configuration variables, see :ref:`configuration` for how to do this.
       However, as a standard  Python project, we document many functions and
       classes as well below, even though these will typically not be needed
       by end users.

    .. currentmodule:: sphinx_gallery

    .. automodule:: sphinx_gallery
       :no-members:
       :no-inherited-members:

    :py:mod:`sphinx_gallery`:

    .. autosummary::
       :toctree: gen_modules/
       :template: module.rst

       gen_gallery
       backreferences
       gen_rst
       scrapers
       py_source_parser
       block_parser
       docs_resolv
       notebook
       downloads
       sorting
       directives

    .. currentmodule:: sphinx_gallery.utils

    .. automodule:: sphinx_gallery.utils
       :no-members:
       :no-inherited-members:

    :py:mod:`sphinx_gallery.utils`:

    .. autosummary::
       :toctree: gen_modules/
       :template: module.rst

       optipng

The important directives are `currentmodule` where we specify which module we are documenting, for our purpose is `sphinx_gallery`. The `autosummary` directive is responsible for generating the `rst` files documenting each module. `autosummary` takes the option toctree which is where the `rst` files are saved and template which is the file that describes how the module `rst` documentation file is to be constructed, finally we write the modules we wish to document, in this case all modules of Sphinx-Gallery.

The template file `module.rst` for the `autosummary` directive has to be saved in the path `_templates/module.rst`. We present our configuration in the following block. The most relevant part is the loop defined between lines 12-21 that parses all the functions/classes of the module. There we have used the `minigallery` directive introduced in the previous section.

We also add a cross referencing label (on line 16) before including the examples mini-gallery. This enables you to reference the mini-gallery for all functions/classes of the module using `:ref:`sphx_glr_backref_<fun/class>``, where ‘<fun/class>’ is the full path to the function/class using dot notation (e.g., `sphinx_gallery.backreferences.identify_names`). For example, see: Examples using sphinx_gallery.backreferences.identify_names.

     1{{ fullname }}
     2{{ underline }}
     3
     4.. automodule:: {{ fullname }}
     5
     6   {% block functions %}
     7   {% if functions %}
     8
     9   Functions
    10   ---------
    11
    12   {% for item in functions %}
    13
    14   .. autofunction:: {{ item }}
    15
    16   .. _sphx_glr_backref_{{fullname}}.{{item}}:
    17
    18   .. minigallery:: {{fullname}}.{{item}}
    19       :add-heading:
    20
    21   {%- endfor %}
    22   {% endif %}
    23   {% endblock %}
    24
    25   {% block classes %}
    26   {% if classes %}
    27
    28   Classes
    29   -------
    30
    31   {% for item in classes %}
    32   .. autoclass:: {{ item }}
    33      :members:
    34
    35   .. _sphx_glr_backref_{{fullname}}.{{item}}:
    36
    37   .. minigallery:: {{fullname}}.{{item}}
    38       :add-heading:
    39
    40   {%- endfor %}
    41   {% endif %}
    42   {% endblock %}
    43
    44   {% block exceptions %}
    45   {% if exceptions %}
    46
    47   Exceptions
    48   ----------
    49
    50   .. autosummary::
    51   {% for item in exceptions %}
    52      {{ item }}
    53   {%- endfor %}
    54   {% endif %}
    55   {% endblock %}

### Toggling global variable inspection

By default, Sphinx-Gallery will inspect global variables (and code objects) at the end of each code block to try to find classes of variables and method calls. It also tries to find methods called on classes. For example, this code:

    lst = [1, 2]
    fig, ax = plt.subplots()
    ax.plot(lst)

should end up with the following links (assuming intersphinx is set up properly):

- `lst`

- `plt.subplots`

- `fig`

- `ax`

- `ax.plot`

However, this feature might not work properly in all instances. Moreover, if variable names get reused in the same script to refer to different classes, it will break.

To disable this global variable introspection, you can use the configuration key:

    sphinx_gallery_conf = {
        ...
        'inspect_global_variables'  : False,
    }

### Stylizing code links using CSS

Each link in the code blocks will be decorated with two or three CSS classes.

1. `sphx-glr-backref-module-*`

     CSS class named after the module where the object is documented. `*` represents the module, e.g., `sphx-glr-backref-module-matplotlib-figure`.

2. `sphx-glr-backref-type-*`

     CSS class named after the type of the object, where `*` represents the object type. This is a sanitized intersphinx type, e.g., a `py:class` will have the CSS class `sphx-glr-backref-type-py-class`.

3. `sphx-glr-backref-instance`

     The third ‘optional’ class that is added only if the object is an instance of a class (rather than, e.g., a class itself, method, or function). By default, Sphinx-Gallery adds the following CSS in `gallery.css`:

         a.sphx-glr-backref-instance {
             text-decoration: none;
         }

     This is done to reduce the visual impact of instance linking in example code. This means that for the following code:

         x = Figure()

     `x`, an instance of a class, will have the `sphx-glr-backref-instance` CSS class, and will not be decorated. `Figure` however, is a class, so will not have the `sphx-glr-backref-instance` CSS class, and will thus be decorated the standard way for links in the given parent styles.

These three CSS classes are meant to give fine-grained control over how different links are decorated. For example, using CSS selectors you could choose to avoid highlighting any `sphx-glr-backref-*` links except for ones that you allowlist (e.g., those from your own module). For example, the following css prevents any module except for matplotlib from being decorated:

    a[class^="sphx-glr-backref-module-"] {
        text-decoration: none;
        color: inherit;
    }
    a[class^="sphx-glr-backref-module-matplotlib"] {
        text-decoration: underline;
    }

There are likely elements other than `text-decoration` that might be worth setting, as well.

You can add these CSS classes by including your own CSS file via the Sphinx configuration `html_static_path`, which will override the default CSS classes in Sphinx-Gallery CSS files.

## Using a custom default thumbnail

In case you want to use your own image for the thumbnail of examples that do not generate any plot, you can specify it by editing your Sphinx `conf.py` file. You need to add to the configuration dictionary a key called default_thumb_file. For example:

    sphinx_gallery_conf = {
        ...
        'default_thumb_file': 'path/to/thumb/file.png',
    }

## Adding line numbers to examples

Line numbers can be displayed in listings by adding the global `line_numbers` setting:

    sphinx_gallery_conf = {
        ...
        'line_numbers': True,
    }

or by adding a comment to the example script, which overrides any global setting:

    # sphinx_gallery_line_numbers = True

## Removing config comments

Some configurations can be specified within a file by adding a special comment with the pattern `# sphinx_gallery_config [= value]` to the example source files. By default, the source files are parsed as is and thus the comment will appear in the example.

To remove the comment from the rendered example set the option:

    sphinx_gallery_conf = {
        ...
        'remove_config_comments': True,
    }

This only removes configuration comments from code blocks, not from text blocks. However, note that technically, file-level configuration comments will work when put in either code blocks or text blocks.

## Add your own first and last notebook cell

Sphinx-Gallery allows you to add your own first and/or last cell to every generated notebook. Adding a first cell can be useful for including code that is required to run properly in the notebook, but not in a `.py` file. By default, no first cell is added.

Adding a last cell can be useful for performing a desired action such as reporting on the user’s environment. By default no last cell is added.

You can choose whatever text you like by modifying the `first_notebook_cell` and `last_notebook_cell` configuration parameters. For example, you can add the following first cell:

    # This cell is added by Sphinx-Gallery
    # It can be customized to whatever you like

Which is achieved by the following configuration:

    sphinx_gallery_conf = {
        ...
        'first_notebook_cell': ("# This cell is added by Sphinx-Gallery\n"
                                "# It can be customized to whatever you like\n"
                                )
    }

A last cell may be added similarly by setting the `last_notebook_cell` parameter:

    sphinx_gallery_conf = {
        ...
        'first_notebook_cell': ("# This cell is added by Sphinx-Gallery\n"
                                "# It can be customized to whatever you like\n"
                                ),
        'last_notebook_cell': "# This is the last cell",
    }

If the value of `first_notebook_cell` or `last_notebook_cell` is set to `None`, then no extra first or last cell will be added to the notebook.

## Adding images to notebooks

When notebooks are produced, by default (`notebook_images = False`) image paths from the image directive in reST documentation blocks (not images generated from code) are included in markdown using their original paths. This includes paths to images expected to be present on the local filesystem which is unlikely to be the case for those downloading the notebook.

By setting `notebook_images = True`, images will be embedded in the generated notebooks via Base64-encoded data URIs. As inclusion of images via data URIs can significantly increase size of the notebook, it’s suggested this only be used when small images are used throughout galleries.

An alternative is to instead provide a prefix string that’ll be used for images e.g. the root URL of where your documentation is hosted. So for example the following configuration:

    sphinx_gallery_conf = {
        ...
        'examples_dirs': ['../examples'],
        'gallery_dirs': ['auto_examples'],
        ...
        'notebook_images': 'https://project.example.com/en/latest/',
        ...
    }

with an example image directive in an reST documentation block being:

    .. image:: ../_static/example.jpg
        :alt: An example image

The image will be added to the generated notebook pointing to the source URL `https://project.example.com/en/latest/_static/example.jpg`. Note the image path in the reST examples above is a relative path, therefore the URL doesn’t contain `auto_examples` as `../` moved up a directory to the documentation source directory. Both relative and absolute (from source directory) paths are supported; so in the example above `/_static/example.jpg` would have resulted in the same URL being produced.

Note that the prefix is applied directly, so a trailing `/` should be included in the prefix if it’s required.

Tip

If building multiple versions of your documentation on a hosted service and using prefix, consider using sphinx build -D command line option to ensure links point to the correct version. For example:

    sphinx-build \
        -b html \
        -D sphinx_gallery_conf.notebook_images="https://project.example.com/docs/${VERSION}/" \
        source_dir build_dir

## Using pypandoc to convert reST to markdown

Sphinx-Gallery can use pypandoc (if installed) to convert reST text blocks to markdown for the iPython notebooks (`.ipynb` files) generated for each example. These are made available for download, along with the raw `.py` version, at the bottom of each example.

The Sphinx-Gallery reST to markdown converter has limited support for more complex reST syntax. If your examples have more complex reST, `pypandoc` may produce better results. By default, the ‘pypandoc’ configuration is set to `False` and `pypandoc` is not used.

To use `pypandoc` you can set:

    sphinx_gallery_conf = {
        ...
        'pypandoc': True,
    }

You can also use pandoc options by setting the `pypandoc.convert_text()` parameters `extra_args` and `filters`. To use these parameters, set the ‘pypandoc’ configuration to be a dictionary of keyword argument(s):

    sphinx_gallery_conf = {
        ...
        'pypandoc': {'extra_args': ['--mathjax',],
                     'filters': ['pandoc-citeproc',],
    }

Warning

Certain pandoc options may result in undesirable effects. Use with caution.

## Using JUnit XML files

Sphinx-Gallery can create a JUnit XML file of your example run times, successes, and failures. To create a file named e.g. `junit-result.xml` in the `/build` output directory, set the configuration key (path is relative to the HTML output directory):

    sphinx_gallery_conf = {
        ...
        'junit': '../test-results/sphinx-gallery/junit.xml',
    }

By default, JUnit XML file generation is disabled (by setting `'junit': ''`). JUnit XML files are useful for example on CircleCI builds, where you can add a line like this to get a summary of your example run times in the CircleCI GUI (which will parse the file path `doc/_build/test-results/sphinx-gallery/junit.xml` and infer the tests came from `sphinx-gallery` based on the nested subdirectory name):

    - store_test_results:
        path: doc/_build/test-results
    - store_artifacts:
        path: doc/_build/test-results

For more information on CircleCI integration, peruse the related CircleCI doc and blog post.

## Setting log level

Sphinx-Gallery logs output at several stages. Warnings can be generated for code that requires case sensitivity (e.g., `plt.subplot` and `plt.Subplot`) when building docs on a filesystem that does not support case sensitive naming (e.g., Windows). In this case, by default a `logger.warning` is emitted, which will lead to a build failure when building with `-W`. The log level can be set with:

    sphinx_gallery_conf = {
        ...
        'log_level': {'backreference_missing': 'warning'},
    }

The only valid key currently is `backreference_missing`. The valid values are `'debug'`, `'info'`, `'warning'`, and `'error'`.

## Disabling download button of all scripts

By default Sphinx-Gallery collects all python scripts and all Jupyter notebooks from each gallery into zip files which are made available for download at the bottom of each gallery. To disable this behavior add to the configuration dictionary in your `conf.py` file:

    sphinx_gallery_conf = {
        ...
        'download_all_examples': False,
    }

## Choosing the thumbnail image

For examples that generate multiple figures, the default behavior will use the first figure created in each as the thumbnail image displayed in the gallery. To change the thumbnail image to a figure generated later in an example script, add a comment to the example script to specify the number of the figure you would like to use as the thumbnail. For example, to use the 2nd figure created as the thumbnail:

    # sphinx_gallery_thumbnail_number = 2

You can also use negative numbers, which counts from the last figure. For example -1 means using the last figure created in the example as the thumbnail:

    # sphinx_gallery_thumbnail_number = -1

The default behavior is `sphinx_gallery_thumbnail_number = 1`. See Choosing the thumbnail figure for an example of this functionality.

## Providing an image for the thumbnail image

An arbitrary image can be used to serve as the thumbnail image for an example. To specify an image to serve as the thumbnail, add a comment to the example script specifying the path to the desired image. The path to the image should be relative to the `conf.py` file and the comment should be somewhere below the docstring (ideally in a code block, see Removing config comments).

For example, the following defines that the image `demo.png` in the folder `_static/` should be used to create the thumbnail:

    # sphinx_gallery_thumbnail_path = '_static/demo.png'

Note that `sphinx_gallery_thumbnail_number` overrules `sphinx_gallery_thumbnail_path`. See Providing a figure for the thumbnail image for an example of this functionality.

## Controlling thumbnail behaviour in failing examples

By default, expected failing examples will have their thumbnail image as a stamp with the word “BROKEN”. This behaviour is controlled by `sphinx_gallery_failing_thumbnail`, which is by default `True`. In cases where control over the thumbnail image is desired, this should be set to `False`. This will return thumbnail behaviour to ‘normal’, whereby thumbnail will be either the first figure created (or the default thumbnail if no figure is created) or provided thumbnail:

    # sphinx_gallery_failing_thumbnail = False

Compare the thumbnails of Example that fails to execute (with normal thumbnail behaviour) (where the option is `False`) and Example that fails to execute (where the option is the default `True`) for an example of this functionality.

## Generate Binder links for gallery notebooks (experimental)

Sphinx-Gallery automatically generates Jupyter notebooks for any examples built with the gallery. Binder makes it possible to create interactive GitHub repositories that connect to cloud resources.

If you host your documentation on a GitHub repository, it is possible to auto-generate a Binder link for each notebook. Clicking this link will take users to a live version of the Jupyter notebook where they may run the code interactively. For more information see the Binder documentation.

Warning

Binder is still beta technology, so there may be instability in the experience of users who click Binder links.

In order to enable Binder links with Sphinx-Gallery, you must specify a few pieces of information in `conf.py`. These are given as a nested dictionary following the pattern below:

    sphinx_gallery_conf = {
      ...
      'binder': {
         # Required keys
         'org': '<github_org>',
         'repo': '<github_repo>',
         'branch': '<github_branch>', # Can be any branch, tag, or commit hash. Use a branch that hosts your docs.
         'binderhub_url': '<binder_url>', # Any URL of a binderhub deployment. Must be full URL (e.g. https://mybinder.org).
         'dependencies': '<list_of_paths_to_dependency_files>',
         # Optional keys
         'filepath_prefix': '<prefix>' # A prefix to prepend to any filepaths in Binder links.
         'notebooks_dir': '<notebooks-directory-name>' # Jupyter notebooks for Binder will be copied to this directory (relative to built documentation root).
         'use_jupyter_lab': <bool> # Whether Binder links should start Jupyter Lab instead of the Jupyter Notebook interface.
         }
    }

If a Sphinx-Gallery configuration for Binder is discovered, the following extra things will happen:

1. The dependency files specified in `dependencies` will be copied to a `binder/` folder in your built documentation.

2. The built Jupyter Notebooks from the documentation will be copied to a folder called `<notebooks_dir/>` at the root of your built documentation (they will follow the same folder hierarchy within the notebooks directory folder.

3. The reST output of each Sphinx-Gallery example will now have a `launch binder` button in it.

4. That button will point to a binder link with the following structure

       <binderhub_url>/v2/gh/<org>/<repo>/<ref>?filepath=<filepath_prefix>/<notebooks_dir>/path/to/notebook.ipynb

Below is a more complete explanation of each field.

org (type: string)

  The GitHub organization where your documentation is stored.

repo (type: string)

  The GitHub repository where your documentation is stored.

branch (type: string)

  A reference to the version of your repository where your documentation exists. For example, if your built documentation is stored on a `gh-pages` branch, then this field should be set to `gh-pages`.

binderhub_url (type: string)

  The full URL to a BinderHub deployment where you want your examples to run. One public BinderHub deployment is at `https://mybinder.org`, though if you (and your users) have access to another, this can be configured with this field.

dependencies (type: list)

  A list of paths (relative to `conf.py`) to dependency files that Binder uses to infer the environment needed to run your examples. For example, a `requirements.txt` file. These will be copied into a folder called `binder/` in your built documentation folder. For a list of all the possible dependency files you can use, see the Binder configuration documentation.

filepath_prefix (type: string | None, default: `None`)

  A prefix to append to the filepath in the Binder links. You should use this if you will store your built documentation in a sub-folder of a repository, instead of in the root.

notebooks_dir (type: string, default: `notebooks`)

  The name of a folder where the built Jupyter notebooks will be copied. This ensures that all the notebooks are in one place (though they retain their folder hierarchy) in case you’d like users to browse multiple notebook examples in one session.

use_jupyter_lab (type: bool, default: `False`)

  Whether the default interface activated by the Binder link will be for Jupyter Lab or the classic Jupyter Notebook interface.

Each generated Jupyter Notebook will be copied to the folder specified in `notebooks_dir`. This will be a subfolder of the sphinx output directory and included with your site build. Binder links will point to these notebooks.

Note

It is not currently possible to host notebooks generated by Sphinx-Gallery with readthedocs.org, as RTD does not provide you with a GitHub repository you could link Binder to. If you’d like to use readthedocs with Sphinx-Gallery and Binder links, you should independently build your documentation and host it on a GitHub branch as well as building it with readthedocs.

See the Sphinx-Gallery Sphinx configuration file for an example that uses the public Binder server.

## Generate JupyterLite links for gallery notebooks (experimental)

Sphinx-Gallery automatically generates Jupyter notebooks for any examples built with the gallery. JupyterLite makes it possible to run an example in your browser. The functionality is quite similar to Binder in the sense that you will get a Jupyter environment where you can run the example interactively as a notebook. The main differences from Binder are:

- with JupyterLite, the example actually runs in your browser, there is no need for a separate machine in the cloud to run your Python code. That means that starting a Jupyter server is generally quicker, no need to wait for the Binder image to be built

- with JupyterLite, the first imports take time. At the time of writing (December 2024) `import scipy` can take ~15-30s. Some innocuously looking Python code may just not work and break in an unexpected fashion. The Jupyter kernel is based on Pyodide, see here for some Pyodide limitations.

- JupyterLite environments are not as flexible as Binder. For example, you can not use a Docker image, but only the default Pyodide environment. That means that some non pure-Python packages may not be available, see list of available packages in Pyodide.

Warning

JupyterLite is still beta technology and less mature than Binder, so there may be instability or unexpected behaviour in the experience of users who click JupyterLite links.

In order to enable JupyterLite links with Sphinx-Gallery, you need to install the jupyterlite-sphinx package. Recent versions of `jupyterlite-sphinx` and Sphinx-Gallery should be compatible, with each other, but we recommend `jupyterlite-sphinx>=0.17.1`. For `jupyterlite-sphinx>=0.8` you also need to install `jupyterlite-pyodide-kernel`. The latest released version is recommended, but recent versions should work as well, this depends on the version of Pyodide that you are using or planning to use.

You then need to add jupyterlite_sphinx to your Sphinx extensions in `conf.py`:

    extensions = [
        ...,
        'jupyterlite_sphinx',
    ]

You can configure JupyterLite integration by setting `sphinx_gallery_conf['jupyterlite']` in `conf.py` like this:

    sphinx_gallery_conf = {
      ...
      'jupyterlite': {
         'use_jupyter_lab': <bool>, # Whether JupyterLite links should start Jupyter Lab instead of the Notebook interface.
         'notebook_modification_function': <str>, # fully qualified name of a function that implements JupyterLite-specific modifications of notebooks
         'jupyterlite_contents': <str>, # where to copy the example notebooks (relative to Sphinx source directory)
         }
    }

Below is a more complete explanation of each field.

use_jupyter_lab (type: bool, default: `True`)

  Whether the default interface activated by the JupyterLite link will be for Jupyter Lab or the RetroLab Notebook interface.

notebook_modification_function (type: str, default: `None`)

  Fully qualified name of a function that implements JupyterLite-specific modifications of notebooks. By default, it is `None` which means that notebooks are not going to be modified. Its signature should be `notebook_modification_function(json_dict: dict, notebook_filename: str) -> None` where `json_dict` is what you get when you do `json.load(open(notebook_filename))`. The function is expected to modify `json_dict` in place by adding notebook cells. It is not expected to write to the file, since `sphinx-gallery` is in charge of this. `notebook_filename` is provided for convenience because it is useful to modify the notebook based on its filename. Potential usages of this function are installing additional packages with a `%pip install seaborn` code cell, or adding a markdown cell to indicate that a notebook is not expected to work inside JupyterLite, for example because it is using packages that are not packaged inside Pyodide. For backward compatibility it can also be a callable but this will not be cached properly as part of the environment by Sphinx.

jupyterlite_contents (type: string, default: `jupyterlite_contents`)

  The name of a folder where the built Jupyter notebooks will be copied, relative to the Sphinx source directory. This is used as Jupyterlite contents.

You can set variables in `conf.py` to configure `jupyterlite-sphinx`, see the jupyterlite-sphinx documentation for more details.

If a Sphinx-Gallery configuration for JupyterLite is discovered, the following extra things will happen:

1. Configure `jupyterlite-sphinx` with some reasonable defaults, e.g. set `jupyterlite_bind_ipynb_suffix = False`.

2. The built Jupyter Notebooks from the documentation will be copied to a folder called `<jupyterlite_contents>/` (relative to Sphinx source directory)

3. If `notebook_modification_function` is not `None`, this function is going to add JupyterLite-specific modifications to notebooks

4. The reST output of each Sphinx-Gallery example will now have a `launch JupyterLite` button in it.

5. That button will point to a JupyterLite link which will start a Jupyter server in your browser with the current example as notebook

If, for some reason, you want to enable the `jupyterlite-sphinx` extension but not use Sphinx-Gallery Jupyterlite integration you can do:

    extensions = [
        ...,
        jupyterlite_sphinx,
    ]

    sphinx_gallery_conf = {
      ...
      'jupyterlite': None
    }

See the Sphinx-Gallery Sphinx configuration file for an example that uses the JupyterLite integration.

## Controlling notebook download links

By default, links to download Jupyter noteooks and launch Binder or JupyterLite (if enabled) are shown only for Python examples. If parsing other file extensions has been enabled (using the `example_extensions` option; see Parsing and executing examples via matching patterns), notebook downloads can be enabled using the `notebook_extensions` option. For example:

    sphinx_gallery_conf = {
        "notebook_extensions": {".py", ".jl"}
    }

where the listed extensions are compared to file names in the gallery directory.

Note

Currently, all generated notebooks specify Python as the kernel. After downloading, the user will need to manually change to the correct kernel.

## Making cell magic executable in notebooks

Often times, tutorials will include bash code for the user to copy/paste into their terminal. This code should not be run when someone is building the documentation, as they will already have those dependencies in their environment. Hence they are normally written as code blocks inside text:

    #%%
    # Installing dependencies
    #
    #     .. code-block:: bash
    #
    #       pip install -q tensorflow
    #       apt-get -qq install curl

This works fine for the `.py` and `.html` files, but causes problems when rendered as an Jupyter notebook. The downloaded `.ipynb` file will not have those dependencies installed, and will not work without running the bash code.

To fix this, we can set the `promote_jupyter_magic` flag in `conf.py`:

    sphinx_gallery_conf = {
        ...
        'promote_jupyter_magic': True,
    }

If this flag is `True`, then when a Jupyter notebook is being built, any code block starting with Jupyter cell magics (e.g. `%%bash` or `%%writefile`) will be turned into a runnable code block.

For our earlier example, we could change the Markdown text to:

    #%%
    # Installing dependencies
    #
    #     .. code-block:: bash
    #
    #       %%bash
    #       pip install -q tensorflow
    #       apt-get -qq install curl

meaning TensorFlow and Curl would be automatically installed upon running the Jupyter notebook. This works for any cell magic (not just those mentioned above) and only affects the creation of Jupyter notebooks.

Warning

It is good practice to ensure the `.py` and `.html` files match the `.ipynb` files as closely as possible. This functionality should only be used when the relevant code is intended to be executed by the end user.

## Building without executing examples

Sphinx-Gallery can parse all your examples and build the gallery without executing any of the scripts. This is just for speed visualization processes of the gallery and the size it takes your website to display, or any use you can imagine for it. To achieve this you need to pass the no plot option in the build process by modifying your `Makefile` with:

    html-noplot:
        $(SPHINXBUILD) -D plot_gallery=0 -b html $(ALLSPHINXOPTS) $(SOURCEDIR) $(BUILDDIR)/html
        @echo
        @echo "Build finished. The HTML pages are in $(BUILDDIR)/html."

Remember that for `Makefile` white space is significant and the indentation are tabs and not spaces.

Alternatively, you can add the `plot_gallery` option to the `sphinx_gallery_conf` dictionary inside your `conf.py` to have it as a default:

    sphinx_gallery_conf = {
        ...
        'plot_gallery': 'False',
    }

The highest precedence is always given to the -D flag of the `sphinx-build` command.

Note

If adding `html-noplot` to your `Makefile`, you will also need to explicitly set the default value for `plot_gallery` in the `sphinx_gallery_conf` dictionary inside your `conf.py` file to avoid a sphinx configuration warning.

## Compressing images

When writing PNG files (the default scraper format), Sphinx-Gallery can be configured to use `optipng` to optimize the PNG file sizes. Typically this yields roughly a 50% reduction in file sizes, thus reducing the loading time of galleries. However, it can increase build time. The allowed values are `'images'` and `'thumbnails'`, or a tuple/list (to optimize both), such as:

    sphinx_gallery_conf = {
        ...
        'compress_images': ('images', 'thumbnails'),
    }

The default is `()` (no optimization) and a warning will be emitted if optimization is requested but `optipng` is not available. You can also pass additional command-line options (starting with `'-'`), for example to optimize less but speed up the build time you could do:

    sphinx_gallery_conf = {
        ...
        'compress_images': ('images', 'thumbnails', '-o1'),
    }

See `$ optipng --help` for a complete list of options.

## Multi-resolution images

Web browsers allow a `srcset` parameter to the `<img>` tag that allows the browser to support responsive resolution images for hi-dpi/retina displays. Sphinx Gallery supports this via the `image_srcset` parameter:

    sphinx_gallery_conf = {
        ...
        'image_srcset': ["2x"],
    }

that saves a 1x image at the normal figure dpi (usually 100 dpi) and a 2x version at twice the density (e.g. 200 dpi). The default is no extra images (`'image_srcset': []`), and you can specify other resolutions if desired as a list: `["2x", "1.5x"]`.

The matplotlib scraper creates a custom image directive, `image-sg` in the rst file:

    .. image-sg:: /examples/images/sphx_glr_test_001.png
        :alt: test
        :srcset: /examples/images/sphx_glr_test_001.png, /examples/images/sphx_glr_test_001_2_0x.png 2.0x
        :class: sphx-glr-single-img

This is converted to html by the custom directive as:

    .. <img src="../_images/sphx_glr_test_001.png" alt="test", class="sphx-glr-single-img",
        srcset="../_images/sphx_glr_test_001.png, ../_images/sphx_glr_test_001_2_0x.png 2.0x>

This leads to a larger website, but clients that support the `srcset` tag will only download the appropriate-sized images.

Note that the `.. image-sg` directive currently ignores other `.. image` directive tags like `width`, `height`, and `align`. It also only works with the html and latex builders.

## Image scrapers

Image scrapers are plugins that allow Sphinx-Gallery to detect images produced during execution of your examples, and then embed them into documentation. Scrapers can be activated by appending scraper names to the `'image_scrapers'` tuple in your Sphinx-Gallery configuration. For example, to scrape matplotlib images you can do:

    sphinx_gallery_conf = {
        ...
        'image_scrapers': ('matplotlib',),
    }

The default value is `'image_scrapers': ('matplotlib',)` which only scrapes Matplotlib images. Note that this includes any images produced by packages that are based on Matplotlib, for example Seaborn or Yellowbrick.

### Matplotlib animations

If you wish to embed `matplotlib.animation.Animation`s as animations rather than a single static image of the animation figure, you should use the matplotlib_animations configuration. It accepts either a bool, indicating whether animations should be enabled, or a tuple of the format: (enabled: bool, format: str):

    sphinx_gallery_conf = {
        ...
        'matplotlib_animations': (True, 'mp4'),
    }

matplotlib_animations is False by default.

Any file format supported by Matplotlib for animations is allowed. If no format is specified (i.e., it is a single bool), or it is None, then the format is determined by `rcParams['animation.html']` and related options in your matplotlib rcParams. This means that it can be set inside your code block, though note that Sphinx-Gallery will reset Matplotib defaults before each example file executes (see Resetting modules).

If the format is `'html5'` or `'jshtml'`, the animation will effectively be embedded in the resulting HTML file. Otherwise the animation will be saved in an external file, thus reducing the size of the ReST file generated. If you request a format that saves to an external file, you will need the sphinxcontrib-video extension installed in your environment.

Note that while `matplotlib_animations` allows you to set the `rcParams['animation.html']` globally, setting it inside a code block will override the global setting.

It’s also recommended to ensure that “FFmpeg” or “imagemagick” is available as a `writer`. Use `matplotlib.animation.ImageMagickWriter.isAvailable()` or `matplotlib.animation.FFMpegWriter.isAvailable()` to check. We recommend FFMpeg writer, unless you are using Matplotlib <3.3.1.

The following scrapers are supported:

- matplotlib

    Sphinx-Gallery maintains a scraper for `matplotlib` figures via the string `'matplotlib'`.

- PyVista

    PyVista maintains a scraper (for PyVista >= 0.20.3) enabled by the string `'pyvista'`.

- PyGMT

    See their website for more information on how to integrate with Sphinx-Gallery.

- qtgallery

    This library provides a scraper for Qt windows. See their repository for instructions on integrating with Sphinx-Gallery.

It is possible to write custom scrapers for images generated by packages outside of those listed above. This is accomplished by writing your own Python function to define how to detect and retrieve images produced by an arbitrary package. For instructions, see Write a custom image scraper. If you come up with an implementation that would be useful for general use (e.g., a custom scraper for a plotting library) feel free to add it to the list above (see discussion here)!

## Using multiple code blocks to create a single figure

By default, images are scraped following each code block in an example. Thus, the following produces two plots, with one plot per code block:

    # %%
    # This first code block produces a plot with two lines

    import matplotlib.pyplot as plt
    plt.plot([1, 0])
    plt.plot([0, 1])

    # %%
    # This second code block produces a plot with one line

    plt.plot([2, 2])
    plt.show()

However, sometimes it can be useful to use multiple code blocks to create a single figure, particularly if the figure takes a large number commands that would benefit from being interleaved with text blocks. The optional flag `sphinx_gallery_defer_figures` can be inserted as a comment anywhere in a code block to defer the scraping of images to the next code block (where it can be further deferred, if desired). The following produces only one plot:

    # %%
    # This first code block does not produce any plot

    import matplotlib.pyplot as plt
    plt.plot([1, 0])
    plt.plot([0, 1])
    # sphinx_gallery_defer_figures

    # %%
    # This second code block produces a plot with three lines

    plt.plot([2, 2])
    plt.show()

## Controlling the layout of multiple figures from the same code block

By default, multiple figures generated from the same code block are stacked side-by-side. Particularly for wide figures, this can lead to cases where images are highly shrunk, losing their legibility. This behaviour can be controlled using two optional variables:

- a file-wide `sphinx_gallery_multi_image` variable

- a code block-specific `sphinx_gallery_multi_image_block` variable

The default behaviour is to treat these variables as being set to `"multi"`, which causes figures to be stacked side-by-side. Setting these variables to `"single"` will allow figures produced from a code block to be displayed as a single column.

For instance, adding:

    # sphinx_gallery_multi_image = "single"

somewhere in an example file will cause images from all code blocks where multiple figures are produced to be displayed in a single column.

Alternatively, adding:

    # sphinx_gallery_multi_image_block = "single"

to a code block will cause multiple figures from only that code block to be displayed in a single column.

Conversely, if `sphinx_gallery_multi_image = "single"` is set for the whole file, adding `sphinx_gallery_multi_image_block = "multi"` can restore the default behaviour for a single code block.

See the example Force plots to be displayed on separate lines for a demonstration of this functionality.

## Hiding lines of code

Normally, Sphinx-Gallery will render every line of Python code when building HTML and iPython notebooks. This is usually desirable, as we want to ensure the Python source files, HTML, and iPython notebooks all do the same thing.

However, it is sometimes useful to have Python code that runs, but is not included in any user-facing documentation. For example, suppose we wanted to add some `assert` statements to verify the docs were built successfully, but did not want these shown to users. We could use the `sphinx_gallery_start_ignore` and `sphinx_gallery_end_ignore` flags to achieve this:

    model.compile()
    # sphinx_gallery_start_ignore
    assert len(model.layers) == 5
    assert model.count_params() == 219058
    # sphinx_gallery_end_ignore
    model.fit()

When the HTML or iPython notebooks are built, this code block will be shown as:

    model.compile()
    model.fit()

The `sphinx_gallery_start_ignore` and `sphinx_gallery_end_ignore` flags may be used in any code block, and multiple pairs of flags may be used in the same block. Every start flag must always have a corresponding end flag, or an error will be raised during doc generation. These flags and the code between them are always removed, regardless of what `remove_config_comments` is set to.

Note that any output from the ignored code will still be captured.

Warning

This flag should be used sparingly, as it makes the `.py` source files less equivalent to the generated `.html` and `.ipynb` files. It is bad practice to use this when other methods that preserve this relationship are possible.

## Generating dummy images

For quick visualization of your gallery, especially during the writing process, Sphinx-Gallery allows you to build your gallery without executing the code (see Building without executing examples and filename/ignore patterns). This however, can cause warnings about missing image files if you have manually written links to automatically generated images. To prevent these warnings you can tell Sphinx-Gallery to create a number of dummy images for an example.

For example, you may have an example (‘my_example.py’) that generates 2 figures, which you then reference manually elsewhere, e.g.,:

    Below is a great figure:

    .. figure:: ../auto_examples/images/sphx_glr_my_example_001.png

    Here is another one:

    .. figure:: ../auto_examples/images/sphx_glr_my_example_002.png

To prevent missing image file warnings when building without executing, you can add the following to the example file:

    # sphinx_gallery_dummy_images=2

This will cause Sphinx-Gallery to generate 2 dummy images with the same naming convention and stored in the same location as images that would be generated when building with execution. No dummy images will be generated if there are existing images (e.g., from a previous run of the build), so they will not be overwritten.

Note

This configuration only works when the example is set to not execute (i.e., the `plot_gallery` is `'False'`, the example is in ignore_pattern or the example is not in `filename_pattern` - see filename/ignore patterns). This means that you will not need to remove any `sphinx_gallery_dummy_images` lines in your examples when you switch to building your gallery with execution.

## Resetting modules

Often you wish to “reset” the behavior of your visualization packages in order to ensure that any changes made to plotting behavior in one example do not propagate to the other examples.

By default, before each example file executes, Sphinx-Gallery will reset `matplotlib` (by using `matplotlib.pyplot.rcdefaults()` and reloading submodules that populate the units registry) and `seaborn` (by trying to unload the module from `sys.modules`). This is equivalent to the following configuration:

    sphinx_gallery_conf = {
        ...
        'reset_modules': ('matplotlib', 'seaborn'),
    }

Currently, Sphinx-Gallery natively supports resetting `matplotlib` and `seaborn`. However, you can also add your own custom function to this tuple in order to define resetting behavior for other visualization libraries.

To do so, follow the instructions in Resetting before each example.

### Order of resetting modules

By default, Sphinx-Gallery will reset modules before each example is run. The choices for `reset_modules_order` are `before` (default), `after`, and `both`. If the last example run in Sphinx-Gallery modifies a module, it is recommended to use `after` or `both` to avoid leaking out a modified module to other parts of the Sphinx build process. For example, set `reset_modules_order` to `both` in the configuration:

    sphinx_gallery_conf = {
        ...
        'reset_modules_order': 'both',
    }

Custom functions can be constructed to have custom functionality depending on whether they are called before or after the examples. See Resetting before each example for more information.

## Dealing with failing Gallery example scripts

As your project evolves some of your example scripts might stop executing properly. Sphinx-Gallery will assist you in the discovery process of those bugged examples. The default behavior is to replace the thumbnail of those examples in the gallery with the broken thumbnail. That allows you to find with a quick glance of the gallery which examples failed. Broken examples remain accessible in the html view of the gallery and the traceback message is written for the failing code block. Refer to example Example that fails to execute to view the default behavior.

The build is also failed exiting with code 1 and giving you a summary of the failed examples with their respective traceback. This way you are aware of failing examples right after the build and can find them easily.

There are some additional options at your hand to deal with broken examples.

### Abort build on first fail

Sphinx-Gallery provides the early fail option. In this mode the gallery build process breaks as soon as an exception occurs in the execution of the examples scripts. To activate this behavior you need to pass a flag at the build process. It can be done by including in your `Makefile`:

    html_abort_on_example_error:
        $(SPHINXBUILD) -D abort_on_example_error=1 -b html $(ALLSPHINXOPTS) $(BUILDDIR)/html
        @echo
        @echo "Build finished. The HTML pages are in $(BUILDDIR)/html."

Remember that for `Makefile` white space is significant and the indentation are tabs and not spaces.

Alternatively, you can add the `abort_on_example_error` option to the `sphinx_gallery_conf` dictionary inside your `conf.py` configuration file to have it as a default:

    sphinx_gallery_conf = {
        ...
        'abort_on_example_error': True,
    }

The highest precedence is always given to the -D flag of the `sphinx-build` command.

### Don’t fail the build if specific examples error

It might be the case that you want to keep the gallery even with failed examples. Thus you can configure Sphinx-Gallery to allow certain examples to fail and still exit with a 0 exit code. For this you need to list all the examples you want to allow to fail during build. Change your conf.py accordingly:

    sphinx_gallery_conf = {
        ...
        'expected_failing_examples': ['../examples/plot_raise.py']
    }

Here you list the examples you allow to fail during the build process, keep in mind to specify the full relative path from your conf.py to the example script.

Note

If an example is expected to fail, Sphinx-Gallery will error if the example runs without error.

### Never fail the build on error

Sphinx-Gallery can be configured to only log warnings when examples fail. This means that sphinx will only exit with a non-zero exit code if the `-W` flag is passed to `sphinx-build`. This can be enabled by setting:

    sphinx_gallery_conf = {
        ...
        'only_warn_on_example_error': True
    }

### Build examples in parallel

Sphinx-Gallery can be configured to run examples simultaneously using `joblib`. This can be enabled by setting:

    sphinx_gallery_conf = {
        ...
        'parallel': 2,
    }

If an `int`, then that number of jobs will be passed to `joblib.Parallel`. If `True`, then the same number of jobs will be used as the `-j` flag for Sphinx.

Warnings emitted by `joblib` during documentation building (e.g., the `UserWarning` about a worker restarting) are emitted during gallery generation at the same time as warnings from example code execution. These can be filtered out with `warnings.filterwarnings` (see Removing warnings). This is particularly important to do if you have tweaked warning handling in your documentation build to treat warnings as errors, e.g., with a line like `warnings.filterwarnings("error)` which converts all warnings into errors. In this case, if joblib emits a warning during build of an example, this example will fail unexpectedly unless they are filtered out. Note that this differs from the warnings affected by the `- W` / `--fail-on-warning` `sphinx-build` flag, which converts Sphinx warnings during documentation building into errors.

Warning

Some packages might not play nicely with parallel processing, so this feature is considered experimental!

For example, you might need to set variables or call functions in a custom resetter to ensure that all spawned processes are properly set up and torn down. Parallelism is achieved through the Loky backend of joblib, see Embarrassingly parallel for loops for documentation of many relevant conisderations (e.g., pickling, oversubscription of CPU resources, etc.).

Using parallel building will also disable memory measurements.

## Enabling the example recommender system

Sphinx-Gallery can be configured to generate content-based recommendations for an example gallery. A list of related examples is automatically generated by computing the closest examples in the TF-IDF space of their text contents. Only examples within a single gallery (including it’s sub-galleries) are used to compute the closest examples. The most similar content is then displayed at the bottom of each example as a set of thumbnails.

The recommender system can be enabled by setting `enable` to `True`. To configure it, pass a dictionary to the `sphinx_gallery_conf`, e.g.:

    sphinx_gallery_conf = {
        ...
        "recommender": {"enable": True, "n_examples": 5, "min_df": 3, "max_df": 0.9},
    }

The only necessary parameter is `enable`. If any other parameters is not specified, the default value is used. Below is a more complete explanation of each field:

enable (type: bool, default: False)

  Whether to generate recommendations inside the example gallery. Enabling this feature requires adding numpy to the dependencies.

n_examples (type: int, default: 5)

  Number of most relevant examples to display.

min_df (type: float in range [0.0, 1.0] | int, default: 3)

  When building the vocabulary ignore terms that have a document frequency strictly lower than the given threshold. If float, the parameter represents a proportion of documents, integer represents absolute counts. This value is also called cut-off in the literature.

max_df (type: float in range [0.0, 1.0] | int, default: 0.9)

  When building the vocabulary ignore terms that have a document frequency strictly higher than the given threshold. If float, the parameter represents a proportion of documents, integer represents absolute counts.

rubric_header (type: str, default: “Related examples”)

  Customizable rubric header. It can be edited to more descriptive text or to add external links, e.g. to the API doc of the recommender system on the Sphinx-Gallery documentation.

The parameters `min_df` and `max_df` can be customized by the user to trim the very rare/very common words. This may improve the recommendations quality, but more importantly, it spares some computation resources that would be wasted on non-informative tokens.

Currently example recommendations are only computed for `.py` files.

## Setting gallery thumbnail size

By default Sphinx-Gallery will generate thumbnails at size `(400, 280)`. The thumbnail image will then be scaled to the size specified by `thumbnail_size`, adding pillarboxes or letterboxes as necessary to maintain the original aspect ratio. The default `thumbnail_size` is `(400, 280)` (no scaling) and can be changed via the `thumbnail_size` configuration, e.g.:

    sphinx_gallery_conf = {
        ...
        'thumbnail_size': (250, 250),
    }

The gallery uses various CSS classes to display these thumbnails, which default to maximum 160x112px. To change this you can modify the default CSS by including your own CSS file via the Sphinx configuration `html_static_path` (which will override default CSS classes in Sphinx-Gallery CSS files). The following CSS would display the images at 250x250px instead of the default 160x112px:

    .sphx-glr-thumbcontainer {
        min-height: 320px !important;
        margin: 20px !important;
    }
    .sphx-glr-thumbcontainer .figure {
        width: 250px !important;
    }
    .sphx-glr-thumbcontainer img {
        max-height: 250px !important;
        width: 250px !important;
    }
    .sphx-glr-thumbcontainer a.internal {
        padding: 270px 10px 0 !important;
    }

Note

The default value of `thumbnail_size` will change from `(400, 280)` (2.5x maximum specified by CSS) to `(320, 224)` (2x maximum specified by CSS) in version 0.9.0. This is to prevent unnecessary over-sampling.

## Minimal reported time

By default, Sphinx-Gallery logs and embeds in the html output the time it took to run each script. If the majority of your examples runs quickly, you may not need this information.

The `min_reported_time` parameter can be set to a number of seconds. The duration of scripts that ran faster than that amount will not be logged nor embedded in the html output.

## Write computation times

Set to `False` if you want to omit computation times from all gallery outputs. This helps with reproducible builds. Default is `True` unless the `SOURCE_DATE_EPOCH` environment variable is set.

## Showing memory consumption

Sphinx-Gallery can use `memory_profiler`, if installed, to report the peak memory during the run of an example. After installing `memory_profiler`, you can do:

    sphinx_gallery_conf = {
        ...
        'show_memory': True,
    }

It’s also possible to use your own custom memory reporter, for example if you would rather see the GPU memory. In that case, `show_memory` must be a callable that takes a single function to call (i.e., one generated internally to run an individual script code block), and returns a two-element tuple containing:

1. The memory used in MiB while running the function, and

2. The function output

A version of this that would always report 0 memory used would be:

    sphinx_gallery_conf = {
        ...
        'show_memory': lambda func: (0., func()),
    }

## Show signature

By default, Sphinx-Gallery writes a Generated by … notice in the generated output.

The `show_signature` parameter can be used to disable it.

## Controlling what output is captured

Note

Configure `capture_repr` to be an empty tuple (i.e., capture_repr: ()) to return to the output capturing behaviour prior to release v0.5.0.

The `capture_repr` configuration allows the user to control what output is captured, while executing the example `.py` files, and subsequently incorporated into the built documentation. Data directed to standard output is always captured. The value of the last statement of each code block, if it is an expression, can also be captured. This can be done by providing the name of the ‘representation’ method to be captured in the `capture_repr` tuple, in order of preference. The representation methods currently supported are:

- `__repr__` - returns the official string representation of an object. This is what is returned when your Python shell evaluates an expression.

- `__str__` - returns a string containing a nicely printable representation of an object. This is what is used when you `print()` an object or pass it to `format()`.

- `_repr_html_` - returns a HTML version of the object. This method is only present in some objects, for example, pandas dataframes.

Output capture can be controlled globally by the `capture_repr` configuration setting, file-by-file by adding a comment to the example file, which overrides any global setting:

    # sphinx_gallery_capture_repr = ()

, or block-by-block by adding a comment to the code block, which overrides any global or file setting:

    # sphinx_gallery_capture_repr_block = ()

The default setting is:

    sphinx_gallery_conf = {
        ...
        'capture_repr': ('_repr_html_', '__repr__'),
    }

With the default setting Sphinx-Gallery would first attempt to capture the `_repr_html_` of the last statement of a code block, if it is an expression. If this method does not exist for the expression, the second ‘representation’ method in the tuple, `__repr__`, would be captured. If the `__repr__` also does not exist (unlikely for non-user defined objects), nothing would be captured. Data directed to standard output is always captured. For several examples, see Capturing output representations.

To capture only data directed to standard output, configure `'capture_repr'` to be an empty tuple: `'capture_repr': ()`. This will imitate the behaviour of Sphinx-Gallery prior to v0.5.0.

From another perspective, take for example the following code block:

    print('Hello world')
    a=2
    a  # this is an expression

`'Hello world'` would be captured for every `capture_repr` setting as this is directed to standard output. Further,

- if `capture_repr` is an empty tuple, nothing else would be captured.

- if `capture_repr` is `('__repr__')`, `2` would also be captured.

- if `capture_repr` is `('_repr_html_', '__repr__')` (the default) Sphinx-Gallery would first attempt to capture `_repr_html_`. Since this does not exist for `a`, it will then attempt to capture `__repr__`. The `__repr__` method does exist for `a`, thus `2` would be also captured in this case.

Matplotlib note: if the `'capture_repr'` tuple includes `'__repr__'` and/or `'__str__'`, code blocks which have a Matplotlib function call as the last expression will generally produce a yellow output box in the built documentation, as well as the figure. This is because matplotlib function calls usually return something as well as creating/amending the plot in standard output. For example, `matplotlib.plot()` returns a list of `Line2D` objects representing the plotted data. This list has a `__repr__` and a `__str__` method which would thus be captured. You can prevent this by:

- assigning the (last) plotting function to a temporary variable. For example:

      import matplotlib.pyplot as plt

      _ = plt.plot([1, 2, 3, 4], [1, 4, 9, 16])

- add `plt.show()` (which does not return anything) to the end of your code block. For example:

      import matplotlib.pyplot as plt

      plt.plot([1, 2, 3, 4], [1, 4, 9, 16])
      plt.show()

- add a `# sphinx_gallery_capture_repr_block = ()` comment to the code block. The unwanted string output will not occur if `'capture_repr'` is an empty tuple or, at least, does not contain `__repr__` or `__str__`. For example:

      # sphinx_gallery_capture_repr_block = ()
      import matplotlib.pyplot as plt

      plt.plot([1, 2, 3, 4], [1, 4, 9, 16])

Note for Plotly users

The suggestions above also apply to Plotly users. Plotly figures have several update methods that implicitly return the updated figure object. You can set a block-level `# sphinx_gallery_capture_repr_block = ()` comment to prevent these from being captured, or assign the return values to a variable (e.g., `fig = fig.update_layout(...)`).

### Prevent capture of certain classes

If you wish to capture a representation of the last expression of each code blocks unless the last expression is of a certain type, you can use `'ignore_repr_types'`. `'ignore_repr_types'` is by default an empty raw string (`r''`), meaning no types are ignored. To exclude specific type(s) from being captured, `'ignore_repr_types'` can be set to a regular expression matching the name(s) of the type(s) to be excluded.

For example, the configuration below would capture the `__repr__` of the last expression of each code block unless the name of the `type()` of the last expression includes the string ‘matplotlib.text’ or ‘matplotlib.axes’. This would prevent capturing of all subclasses of ‘matplotlib.text’, e.g. expressions of type ‘matplotlib.text.Annotation’, ‘matplotlib.text.OffsetFrom’ etc. Similarly subclasses of ‘matplotlib.axes’ (e.g. ‘matplotlib.axes.Axes’, ‘matplotlib.axes.Axes.plot’ etc.) will also not be captured.

    sphinx_gallery_conf = {
        ...
        'capture_repr': ('__repr__'),
        'ignore_repr_types': r'matplotlib\.(text|axes)',
    }

## Nesting gallery sections

`nested_sections` lets you control how gallery `index.rst` files are generated when your gallery has subsections (sub-folders inside examples_dirs, aka sub-galleries). This can be useful for controlling sidebar appearance. The default is set to `nested_sections=True` because it generally works with the popular pydata-sphinx-theme theme. It can however, cause undesirable duplication in the sidebar with other themes so users are advised to choose the most suitable `nested_sections` setting for their theme.

With default `nested_sections=True`, Sphinx-Gallery will use the `GALLERY_HEADER.[ext]` (or `README.[ext]` for backward-compatibility) files for the parent gallery and each subsection to build separate index files for the parent gallery and each subsection. subsection index files will contain the subsection’s header (from the `GALLERY_HEADER.[ext]` file) and a toctree linking to each gallery example in the subsection. The parent gallery’s main `index.rst` file will contain, in sequence:

- parent gallery header followed by gallery thumbnails,

- a toctree linking to each gallery example in the parent gallery,

- subsection header followed by subsection thumbnails, for all subsections,

- a second toctree, at the end of the file, linking to all subsection index files.

The generated file structure and toctrees mimic that of the parent gallery folder, which may be needed for generating sidebars with nested sections for some themes.

For other themes, having two toctrees can cause undesirable duplication in the sidebar. In this case you can try moving all parent gallery examples to their own sub-folder, as this will result in a single toctree in the parent gallery `index.rst`, or using `nested_sections=False`.

`nested_sections=False` makes Sphinx-Gallery behave as it used to prior to version 0.10.2. Specifically, it will generate a single index file for the whole gallery. This index file will contain headers for the parent gallery and each subsection, with each header followed by a toctree that links to every example in the parent gallery/subsection. For some themes, sidebars generated using these toctrees would list all gallery items with a flat structure and not reflect the nested folder structure of sub-galleries.

## Manually passing files

By default, Sphinx-Gallery creates all the files that are written in the sphinx-build directory, either by generating reST and images from a `*.py` in the gallery-source, or from creating `index.rst` from `GALLERY_HEADER.rst` (or `README.[rst/txt]` for backward-compatibility) in the gallery-source. However, sometimes it is desirable to pass files from the gallery-source to the sphinx-build. For example, you may want to pass an image that a gallery refers to, but does not generate itself. You may also want to pass raw reST from the gallery-source to the sphinx-build, because that material fits in thematically with your gallery, but is easier to write as reST. To accommodate this, you may set `copyfile_regex` in `sphinx_gallery_conf`. The following copies across reST files.

    sphinx_gallery_conf = {
        ...
       'copyfile_regex': r'.*\.rst',
    }

Note that if you copy across reST files, for instance, it is your responsibility to ensure that they are in a sphinx `toctree` somewhere in your document. You can, of course, add a `toctree` to your `GALLERY_HEADER.rst`.

### Manually passing `index.rst`

You can bypass Sphinx-Gallery automatically creating an `index.rst` from a `GALLERY_HEADER.rst` in a gallery directory or nested sub-gallery directory. If your `copyfile_regex` includes `index.rst`, and you have an `index.rst` in the gallery-source (i.e., a examples_dirs directory), Sphinx-Gallery will use that instead and not make an index file for that gallery or any of its sub-galleries. If you pass your own `index.rst` file, you are responsible for adding your own Sphinx `toctree` in that index (or elsewhere in your Sphinx documentation) that includes any gallery items or other files in that directory. You are also responsible for adding any necessary `index.rst` files for that gallery’s sub-galleries.

## Showing API Usage

Graphs and documentation of both unused API entries and the examples that each API entry is used in are generated in the sphinx output directory under `sg_api_usage.html`. See the Sphinx-Gallery API usage documentation and graphs for example. In large projects, there are many modules and, since a graph of API usage is generated for each module, this can use a lot of resources so `show_api_usage` is set to `'unused'` by default. The unused API entries are all shown in one graph so this scales much better for large projects. Setting `show_api_usage` to `True` will make one graph per module showing all of the API entries connected to the example that they are used in. This could be helpful for making a map of which examples to look at if you want to learn about a particular module. Setting `show_api_usage` to `False` will not make any graphs or documentation about API usage. Note, `graphviz` is required for making the unused and used API entry graphs.

### Ignoring API entries

By default, `api_usage_ignore='.*__.*__'` ignores files that match this regular expression in documenting and graphing the usage of API entries within the example gallery. This regular expression can be modified to ignore any kind of file that should not be considered. The default regular expression ignores functions like `__len__()` for which it may not be desirable to document if they are used in examples.