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EXREX

Irregular methods for regular expressions.

Exrex is a command line tool and python module that generates all - or random - matching strings to a given regular expression and more. It's pure python, without external dependencies.

There are regular expressions with infinite matching strings (eg.: [a-z]+), in these cases exrex limits the maximum length of the infinite parts.

Exrex uses generators, so the memory usage does not depend on the number of matching strings.

Features

Generating all matching strings
Generating a random matching string
Counting the number of matching strings
Simplification of regular expressions

Installation

To install exrex, simply:

$ pip install exrex

$ easy_install exrex

Usage

as python module

>>> import exrex

>>> exrex.getone('(ex)r\\1')
'exrex'

>>> list(exrex.generate('((hai){2}|world!)'))
['haihai', 'world!']

>>> exrex.getone('\d{4}-\d{4}-\d{4}-[0-9]{4}')
'3096-7886-2834-5671'

>>> exrex.getone('(1[0-2]|0[1-9])(:[0-5]\d){2} (A|P)M')
'09:31:40 AM'

>>> exrex.count('[01]{0,9}')
1023

>>> print '\n'.join(exrex.generate('This is (a (code|cake|test)|an (apple|elf|output))\.'))
This is a code.
This is a cake.
This is a test.
This is an apple.
This is an elf.
This is an output.

>>> print exrex.simplify('(ab|ac|ad)')
(a[bcd])

Command line usage

> exrex --help
usage: exrex.py [-h] [-o FILE] [-l] [-d DELIMITER] [-v] REGEX

exrex - regular expression string generator

positional arguments:
  REGEX                 REGEX string

optional arguments:
  -h, --help            show this help message and exit
  -o FILE, --output FILE
                        Output file - default is STDOUT
  -l N, --limit N       Max limit for range size - default is 20
  -c, --count           Count matching strings
  -m N, --max-number N  Max number of strings - default is -1
  -r, --random          Returns a random string that matches to the regex
  -s, --simplify        Simplifies a regular expression
  -d DELIMITER, --delimiter DELIMITER
                        Delimiter - default is \n
  -v, --verbose         Verbose mode

Examples:

$ exrex '[asdfg]'
a
s
d
f
g

$ exrex -r '(0[1-9]|1[012])-\d{2}'
09-85

$ exrex '[01]{10}' -c
1024

Bugs

Bugs or suggestions? Visit the issue tracker.

Documentation

http://exrex.readthedocs.org/en/latest/

TODO

Command line switches to change default character sets/ranges/range limits (eg. for '.','\s'..) (40%)
Extend categories (re.sre_parse.CATEGORIES) (30%)
Improve setup.py
More verbose code
Documentation
Optimizations
Generation of n different random matching string
Memory usage reduction (100%?) - generators
Count the number of matching strings - (100%?)
Unicode support (100%)
Handle grouprefs (100%)
Python3 compatibility (100%) ( >= python3.3)

License

exrex is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

exrex is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with exrex. If not, see < http://www.gnu.org/licenses/ >.

(C) 2012- by Adam Tauber, <asciimoo@gmail.com>

Fun/arts

Boat: exrex '( {20}(\| *\\|-{22}|\|)|\.={50}| ( ){0,5}\\\.| {12}~{39})'
Eyes: exrex '(o|O|0)(_)(o|O|0)'

Similar projects

Tools that generate a list of all possible strings that match a given pattern:

regldg (features a live demo on the website)
regex-genex (supports using multiple regex patterns simultaneously)

Tools that generate random strings, one by one, that match a given pattern:

randexp.js (features several live demos on the website)
rstr.xeger (a method of the rstr Python module)

Profiling

python -m cProfile exrex.py '[a-zA-Z][a-zA-Z][a-zA-Z][a-zA-Z]' -o /dev/null
python -m cProfile exrex.py '[0-9]{6}' -o /dev/null

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