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About: Why another tool for parsing?

RE|PARSE

Python library/tools for combining and parsing using Regular Expressions in a maintainable way

[Build Status Download/View Source on Github] [Docs at ReadtheDocs]

This library also allows you to:

  • Maintain a database of Regular Expressions
  • Combine them together using Patterns
  • Search, Parse and Output data matched by combined Regex using Python functions.

This library basically just gives you a way to combine Regular Expressions together and hook them up to some callback functions in Python.

A Taste / Getting Started

(See the examples/ directory for a full code examples)

Say your fashionista friend must know what colors their friends like at certain times. Luckily for you two, your friend’s friends are blogging fanatics and you have downloaded thousands of text documents containing their every thought.

So you want to get (color and time) or [('green', datetime.time(23, 0))] out of text like:

blah blah blah go to the store to buy green at 11pm! blah blah

If you need scan/search/parse/transform some unstructured input and get some semi-structured data out of it RE|PARSE might be able to help.

First structure some Regular Expressions (Here, in Yaml)

Color:
    Basic Color:
        Expression: (Red|Orange|Yellow|Green|Blue|Violet|Brown|Black)
        Matches: Orange | Green
        Non-Matches: White
        Groups:
          - Color

Time:
    Basic Time:
        Expression: ([0-9]|[1][0-2]) \s? (am|pm)
        Matches: 8am | 3 pm
        Non-Matches: 8a | 8:00 am | 13pm
        Groups:
          - Hour
          - AMPM

Then structure some Patterns with those expressions (Yaml)

BasicColorTime:
  Order: 1
  Pattern: |
    <Color> \s? at \s? <Time>
  # Angle brackets detonate expression groups
  # Multiple expressions in one group are combined together

Some callback functions (in Python)

from datetime import time
def color_time(Color=None, Time=None):
    Color, Hour, Period = Color[0], int(Time[0]), Time[1]
    if Period == 'pm':
        Hour += 12
    Time = time(hour=Hour)

    return Color, Time

Build your parser

from examples.colortime.functions import functions
import reparse


colortime_parser = reparse.parser(
    parser_type=reparse.basic_parser,
    expressions_yaml_path=path + "expressions.yaml",
    patterns_yaml_path=path + "patterns.yaml",
    functions=functions
)

print(colortime_parser("~ ~ ~ go to the store ~ buy green at 11pm! ~ ~"))

Result

[('green', datetime.time(23, 0))]

Cool!

Intrigued? Learn more how to make the magic happen in Howto: How to use RE|PARSE.

Want to read more about what RE|PARSE is and what it can do? More info in About: Why another tool for parsing?

Info

Installation

pip

pip install reparse

manually

  1. If you don’t have them already, RE|PARSE depends on REGEX, and PyYaml. Download those and python setup.py install in their directories. If you are on windows, you may have to find binary installers for these, since they contain modules that have to be compiled.
  2. Download the Zip off of Github (or clone the repo).
  3. Extract and do python setup.py install in the reparse containing the setup.py file directory. You can also just have the reparse/reparse directory in the source tree of your project if you don’t want to install it.
  4. Test with python -c "import reparse", no output means it is probably installed. If you get ImportError: No module named reparse then you might want to recheck your steps.

Support

Need some help? Send me an email at andy@asperous.us and I’ll do my best to help you.

Contribution

The code is located on Github. Send me suggestions, issues, and pull requests and I’ll gladly review them!

Versions

  • 2.0 Major Refactor, Python 3, Better Parser builders
  • 1.1 Fix setup.py
  • 1.0 Release

Licence

The MIT License (MIT)

Copyright (c) 2013 Andrew Chase

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.