Skip to main content

Regular expression reverser for Python

Project description

unmatcher tries to solve the following problem:

Given a regular expression, find any string that matches the expression.

Why? Mostly just because. But one possible application is to generate test data for string processing functions.

Status

PyPI package version License Build Status

Most typical elements of regexes are supported:

  • multipliers: *, +

  • capture groups: |, ( ) (including backreferences)

  • character classes (\d|\w|\s etc.) and character sets ([])

API

unmatcher module exposes a single reverse function. It takes a regular expression - either in text or compiled form - and returns a random string that matches it:

>>> import unmatcher
>>> print unmatcher.reverse(r'\d')
7

Additional arguments can be provided, specifying predefined values for capture groups inside the expression. Use positional arguments for numbered groups ('\1', etc.):

>>> import unmatcher
>>> print unmatcher.reverse(r'<(\w+)>.*</\1>', 'h1')
<h1>1NLNVlrOT4YGyHV3vD7cHvrAl8OHVWDPKgmaE4gUsctboyFYUx</h1>

and keyword arguments for named groups:

>>> import unmatcher
>>> print unmatcher.reverse('(?P<foo>\w+)__(?P=foo)', foo='bar')
bar__bar

Note that a predefined value is not validated against actual subexpression for the capture group.

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

unmatcher-0.1.4.tar.gz (7.4 kB view hashes)

Uploaded Source

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page