# Integrating your objects with IPython

## Tab completion

To change the attributes displayed by tab-completing your object, define a `__dir__(self)` method for it. For more details, see the documentation of the built-in dir() function.

## Rich display

The notebook and the Qt console can display richer representations of objects. To use this, you can define any of a number of `_repr_*_()` methods. Note that these are surrounded by single, not double underscores.

Both the notebook and the Qt console can display `svg`, `png` and `jpeg` representations. The notebook can also display `html`, `javascript`, and `latex`. If the methods don’t exist, or return `None`, it falls back to a standard `repr()`.

For example:

    class Shout(object):
        def __init__(self, text):
            self.text = text

        def _repr_html_(self):
            return "<h1>" + self.text + "</h1>"

## Custom exception tracebacks

Rarely, you might want to display a different traceback with an exception - IPython’s own parallel computing framework does this to display errors from the engines. To do this, define a `_render_traceback_(self)` method which returns a list of strings, each containing one line of the traceback.

Please be conservative in using this feature; by replacing the default traceback you may hide important information from the user.