# Writers

## Common Writer Options

All writer take the following options (specified as keyword arguments to `Barcode.save(filename, options)` or set via `Writer.set_options(options)`, where `options` is a dictionary where keys are option names and values are option values to be set).

Note

See the documentation of the specific writer for special options, only available for this writer.

module_width:

  The width of one barcode module in mm as float. Defaults to 0.2.

module_height:

  The height of the barcode modules in mm as float. Defaults to 15.0.

quiet_zone:

  Distance on the left and on the right from the border to the first (last) barcode module in mm as float. Defaults to 6.5.

font_path:

  Path to the font file to be used. Defaults to DejaVuSansMono (which is bundled with this package).

font_size:

  Font size of the text under the barcode in pt as integer. Font size zero suppresses text. Defaults to 10.

text_distance:

  Distance between the barcode and the text under it in mm as float. Defaults to 5.0.

background:

  The background color of the created barcode as string. Defaults to white.

foreground:

  The foreground and text color of the created barcode as string. Defaults to black.

center_text:

  If true (the default) the text is centered under the barcode else left aligned.

  Added in version 0.6.

Note

Some barcode classes change the above defaults to fit in some kind of specification.

## SVGWriter

Renders barcodes as [optionally, compressed] SVG objects.

In addition to the common writer options you can give the following special option.

compress:

  Boolean value to output a compressed SVG object (.svgz). Defaults to `False`

## ImageWriter

Added in version 0.4b1.

Renders barcodes as image. Supports all the image formats supported by Pillow.

In addition to the common writer options you can give the following special options:

format:

  The image file format as `str`. All formats supported by Pillow are valid (e.g. PNG, JPEG, BMP, …). Defaults to `PNG`.

dpi:

  DPI as `int` to calculate the image size in pixel. This value is used for all mm to px calculations. Defaults to `300`

## Custom writers

It’s possible to create your own writer by inheriting from barcode.writer.BaseWriter.

In your `__init__` method call BaseWriter’s `__init__` and give your callbacks for:

> - `initialize(raw_code)`

> - `paint_module(xpos, ypos, width, color)`

> - `paint_text(xpos, ypos)`

> - `finish()`

Now instantiate a new barcode and give an instance of your new writer as argument. If you now call `render` on the barcode instance your callbacks get called.

## Creating compressed SVGs

Saving a compressed SVG (SVGZ):

    >>> import barcode
    >>> ean = barcode.get('ean13', '123456789102')
    # Now we look if the checksum was added
    >>> ean.get_fullcode()
    '1234567891026'
    >>> filename = ean.save('ean13')
    >>> filename
    'ean13.svg'
    >>> options = dict(compress=True)
    >>> filename = ean.save('ean13', options)
    >>> filename
    'ean13.svgz'

Now you have ean13.svg and the compressed ean13.svgz in your current working directory. Open it and see the result.