datauri

datauri is a small Python library implementing the data: uri scheme defined in RFC2397. The generic format is:

data:[<mediatype>][;base64],<data>

Installation

Install datauri from PyPI using:

pip install datauri

Note: this library is for Python 3 only.

Usage

>>> import datauri

To parse a string containing a data: uri, use parse():

>>> parsed = datauri.parse('data:text/plain,A%20brief%20note')

This returns a parse result:

>>> parsed.media_type
'text/plain'
>>> parsed.data
b'A brief note'
>>> parsed.uri
'data:text/plain,A%20brief%20note'

This is a simple container class with a few attributes:

• The media_type attribute is a string (str) or None in case it was absent. Any (optional) embedded text encoding specifications are not processed in any way; it is up to the application to deal with that.
• The data attribute is a byte string (bytes) with the decoded data. URL encoding and base64 is handled transparently.
• For convenience, the uri attribute contains the input uri.

Parsed URIs compare equal if their media type and data are the same. Instances are hashable, so they can be used as dictionary keys.

Parsing failures will raise a DataURIError:

>>> datauri.parse('invalid')
Traceback (most recent call last):
…
datauri.DataURIError: invalid data uri

The DataURIError subclasses the built-in ValueError, so this will work as expected:

try:
    datauri.parse('invalid')
except ValueError:
    pass

In addition to parsing a string, this library can also discover (and directly parse) any data: URIs found in a larger string:

s = 'long string with data:text/plain,A%20brief%20note and more'
for parsed in datauri.discover(s):
    print(s)

More information

• RFC2397: https://tools.ietf.org/html/rfc2397
• Wikipedia: https://en.wikipedia.org/wiki/Data_URI_scheme
• Mozilla developer documentation: https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/Data_URIs

Known issues

Currently, only parsing has been implemented.

Contributing

Please use Github issues to report problems or propose improvements.

Version history

• 1.0.0

  Initial release.

License

(This is the OSI approved 3-clause "New BSD License".)

Copyright © 2017, EclecticIQ

All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

• Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
• Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
• Neither the name of the author nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.