dateparser – python parser for human readable dates

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dateparser provides modules to easily parse localized dates in almost any string formats commonly found on web pages.

Documentation

Documentation can be found here.

Features

  • Generic parsing of dates in English, Spanish, Dutch, Russian and several other langauges and formats.
  • Generic parsing of relative dates like: '1 min ago', '2 weeks ago', '3 months, 1 week and 1 day ago'.
  • Generic parsing of dates with time zones abbreviations like: 'August 14, 2015 EST', 'July 4, 2013 PST'.
  • Extensive test coverage.

Usage

The most straightforward way is to use the dateparser.parse function, that wraps around most of the functionality in the module.

dateparser.parse(date_string, date_formats=None, languages=None)[source]

Parse date and time from given date string.

Parameters:
  • date_string (str|unicode) – A string representing date and/or time in a recognizably valid format.
  • date_formats (list) –

    A list of format strings using directives as given here. The parser applies formats one by one, taking into account the detected languages.

  • languages (list) – A list of two letters language codes.e.g. [‘en’, ‘es’]. If languages are given, it will not attempt to detect the language.
Returns:

Returns a datetime.datetime if successful, else returns None

Raises:

ValueError - Unknown Language

Relative Dates

>>> parse('1 hour ago')
datetime.datetime(2015, 5, 31, 23, 0)
>>> parse(u'Il ya 2 heures')  # French (2 hours ago)
datetime.datetime(2015, 5, 31, 22, 0)
>>> parse(u'1 anno 2 mesi')  # Italian (1 year 2 months)
datetime.datetime(2014, 4, 1, 0, 0)
>>> parse(u'yaklaşık 23 saat önce')  # Turkish (23 hours ago)
datetime.datetime(2015, 5, 31, 1, 0)
>>> parse(u'Hace una semana')  # Spanish (a week ago)
datetime.datetime(2015, 5, 25, 0, 0)
>>> parse(u'2小时前')  # Chinese (2 hours ago)
datetime.datetime(2015, 5, 31, 22, 0)

Note

Testing above code might return different values for you depending on your environment’s current date and time.

Dependencies

dateparser translates non-english dates to English and uses dateutil module 'parser' to parse the translated date.

Also, it requires PyYAML for its language detection module to work.

Limitations

  • Only Python 2 support for now (Python 3 support will be added in future versions)

Using DateDataParser

dateparser.parse() uses a default parser which tries to detect language every time it is called and is not the most efficient way while parsing dates from the same source.

dateparser.date.DateDataParser provides an alternate and efficient way to control language detection behavior.

The instance of dateparser.date.DateDataParser reduces the number of applicable languages, until only one or no language is left. It assumes the previously detected language for all the next dates and does not try to execute the language detection again after a language is discarded.

This class wraps around the core dateparser functionality, and by default assumes that all of the dates fed to it are in the same language.

class dateparser.date.DateDataParser(languages=None, allow_redetect_language=False)[source]

Class which handles language detection, translation and subsequent generic parsing of string representing date and/or time.

Parameters:
  • languages (list) – A list of two letters language codes.e.g. [‘en’, ‘es’]. If languages are given, it will not attempt to detect the language.
  • allow_redetect_language (bool) – Enables/disables language re-detection.
Returns:

A parser instance

Raises:

ValueError - Unknown Language, TypeError - Languages argument must be a list

get_date_data(date_string, date_formats=None)[source]

Parse string representing date and/or time in recognizeable localized formats. Supports parsing multiple languages.

Parameters:
  • date_string (str|unicode) – A string representing date and/or time in a recognizably valid format.
  • date_formats (list) –

    A list of format strings using directives as given here. The parser applies formats one by one, taking into account the detected languages.

Returns:

a dict mapping keys to datetime.datetime object and period. For example: {‘date_obj’: datetime.datetime(2015, 6, 1, 0, 0), ‘period’: u’day’}

Raises:

ValueError - Unknown Language

Note

Period values can be a ‘day’ (default), ‘week’, ‘month’, ‘year’.

Period represent the granularity of date parsed from the given string.

In the example below, since no day information is present, the day is assumed to be current day 16 from current date (which is June 16, 2015, at the moment of writing this). Hence, the level of precision is month.

>>> DateDataParser().get_date_data(u'March 2015')
{'date_obj': datetime.datetime(2015, 3, 16, 0, 0), 'period': u'month'}

Similarly, for date strings with no day and month information present, level of precision is year and day 16 and month 6 are from current_date.

>>> DateDataParser().get_date_data(u'2014')
{'date_obj': datetime.datetime(2014, 6, 16, 0, 0), 'period': u'year'}

TODO: Timezone issues

Once initialized, dateparser.date.DateDataParser.get_date_data() parses date strings:

>>> from dateparser.date import DateDataParser
>>> ddp = DateDataParser()
>>> ddp.get_date_data(u'Martes 21 de Octubre de 2014')  # Spanish
{'date_obj': datetime.datetime(2014, 10, 21, 0, 0), 'period': u'day'}
>>> ddp.get_date_data(u'13 Septiembre, 2014')  # Spanish
{'date_obj': datetime.datetime(2014, 9, 13, 0, 0), 'period': u'day'}

Warning

It fails to parse English dates in the example below, because Spanish was detected and stored with the ddp instance:

>>> ddp.get_date_data('11 August 2012')

{‘date_obj’: None, ‘period’: ‘day’}

dateparser.date.DateDataParser can also be initialized with known languages:

>>> ddp = DateDataParser(languages=['de', 'nl'])
>>> ddp.get_date_data(u'vr jan 24, 2014 12:49')
{'date_obj': datetime.datetime(2014, 1, 24, 12, 49), 'period': u'day'}
>>> ddp.get_date_data(u'18.10.14 um 22:56 Uhr')
{'date_obj': datetime.datetime(2014, 10, 18, 22, 56), 'period': u'day'}

Documentation

Contents:

Installation

At the command line:

$ pip install dateparser

Or, if you don’t have pip installed:

$ easy_install dateparser

If you want to install from the latest sources, you can do:

$ git clone https://github.com/scrapinghub/dateparser.git
$ cd dateparser
$ python setup.py install

Deploying dateparser in a Scrapy Cloud project

The initial use cases for dateparser were for Scrapy projects doing web scraping that needed to parse dates from websites. These instructions show how you can deploy it in a Scrapy project running in Scrapy Cloud.

Deploying with shub

The most straightforward way to do that is to use the latest version of the shub command line tool.

First, install shub, if you haven’t already:

pip install shub

Then, you can choose between deploying a stable release or the latest from development.

Deploying a stable dateparser release:
  1. Then, use shub to install python-dateutil (we require at least 2.3 version) and PyYAML dependencies from PyPI:

    shub deploy-egg --from-pypi python-dateutil YOUR_PROJECT_ID
    shub deploy-egg --from-pypi PyYAML YOUR_PROJECT_ID
    
  2. Finally, deploy dateparser from PyPI:

    shub deploy-egg --from-pypi dateparser YOUR_PROJECT_ID
    
Deploying from latest sources

Optionally, you can deploy it from the latest sources:

Inside the dateparser root directory:

  1. Run the command to deploy the dependencies:

    shub deploy-reqs YOUR_PROJECT_ID requirements.txt
    
  2. Then, either deploy from the latest sources on GitHub:

    shub deploy-egg --from-url git@github.com:scrapinghub/dateparser.git YOUR_PROJECT_ID
    

Or, just deploy from the local sources (useful if you have local modifications):

shub deploy-egg
Deploying the egg manually

In case you run into trouble with the above procedure, you can deploy the egg manually. First clone the dateparser‘s repo, then inside its directory run the command:

python setup.py bdist_egg

After that, you can upload the egg using Scrapy Cloud’s Dashboard interface under Settings > Eggs section.

Dependencies

Similarly, you can download source and package PyYAML and dateutil (version >= 2.3) as eggs and deploy them like above.

Contributing

Contributions are welcome, and they are greatly appreciated! Every little bit helps, and credit will always be given.

You can contribute in many ways:

Types of Contributions

Report Bugs

Report bugs at https://github.com/scrapinghub/dateparser/issues.

If you are reporting a bug, please include:

  • Your operating system name and version.
  • Any details about your local setup that might be helpful in troubleshooting.
  • Detailed steps to reproduce the bug.
Fix Bugs

Look through the GitHub issues for bugs. Anything tagged with “bug” is open to whoever wants to implement it.

Implement Features

Look through the GitHub issues for features. Anything tagged with “feature” is open to whoever wants to implement it.

Write Documentation

DateParser could always use more documentation, whether as part of the official DateParser docs, in docstrings, or even on the web in blog posts, articles, and such.

Submit Feedback

The best way to send feedback is to file an issue at https://github.com/scrapinghub/dateparser/issues.

If you are proposing a feature:

  • Explain in detail how it would work.
  • Keep the scope as narrow as possible, to make it easier to implement.
  • Remember that contributions are welcome :)

Get Started!

Ready to contribute? Here’s how to set up dateparser for local development.

  1. Fork the dateparser repo on GitHub.

  2. Clone your fork locally:

    $ git clone git@github.com:your_name_here/dateparser.git
    
  3. Install your local copy into a virtualenv. Assuming you have virtualenvwrapper installed, this is how you set up your fork for local development:

    $ mkvirtualenv dateparser
    $ cd dateparser/
    $ python setup.py develop
    
  4. Create a branch for local development:

    $ git checkout -b name-of-your-bugfix-or-feature
    

    Now you can make your changes locally.

  5. When you’re done making changes, check that your changes pass flake8 and the tests, including testing other Python versions with tox:

    $ pip install -r tests/requirements.txt # install test dependencies
    $ flake8 dateparser tests
    $ nosetests
    $ tox
    

    To get flake8 and tox, just pip install them into your virtualenv. (Note that we use max-line-length = 100 for flake8, this is configured in setup.cfg file.)

  6. Commit your changes and push your branch to GitHub:

    $ git add .
    $ git commit -m "Your detailed description of your changes."
    $ git push origin name-of-your-bugfix-or-feature
    
  7. Submit a pull request through the GitHub website.

Pull Request Guidelines

Before you submit a pull request, check that it meets these guidelines:

  1. The pull request should include tests.
  2. If the pull request adds functionality, the docs should be updated. Put your new functionality into a function with a docstring, and add the feature to the list in README.rst.
  3. Check https://travis-ci.org/scrapinghub/dateparser/pull_requests and make sure that the tests pass for all supported Python versions.
  4. Follow the core developers’ advices which aim to ensure code’s consistency regardless of variety approaches used by many contributors.
  5. In case, you are unable to continue working on a PR, please leave a short comment to notify us. We will be pleased to make any changes required to get it done.

Credits

Committers

  • Artur Sadurski
  • Claudio Salazar
  • Elias Dorneles
  • Eugene Amirov
  • Faisal Anees
  • Ismael Carnales
  • Joseph Kahn
  • Mark Baas
  • Marko Horvatić
  • Mateusz Golewski
  • Opp Lieamsiriwong
  • Rajat Goyal
  • Raul Gallegos
  • Shuai Lin
  • Sigit Dewanto
  • Sviatoslav Sydorenko
  • Tom Russell
  • Umair Ashraf
  • Waqas Shabir

History

0.2.1 (2015-07-13)

  • Support for generic parsing of dates with UTC offset.
  • Support for Filipino dates.
  • Improved support for French and Spanish dates.

0.2.0 (2015-06-17)

  • Easy to use parse function
  • Languages definitions using YAML.
  • Using translation based approach for parsing non-english languages. Previously, dateutil.parserinfo was used for language definitions.
  • Better period extraction.
  • Improved tests.
  • Added a number of new simplifications for more comprehensive generic parsing.
  • Improved validation for dates.
  • Support for Polish, Thai and Arabic dates.
  • Support for pytz timezones.
  • Fixed building and packaging issues.

0.1.0 (2014-11-24)

  • First release on PyPI.

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