https://github.com/invl/retry

easy to use retry decorator in python
https://github.com/invl/retry

Last synced: 5 days ago
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easy to use retry decorator in python

• Host: GitHub
• URL: https://github.com/invl/retry
• Owner: invl
• License: other
• Created: 2014-05-21T04:21:55.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2024-07-05T13:16:48.000Z (4 months ago)
• Last Synced: 2024-10-29T16:19:12.807Z (5 days ago)
• Language: Python
• Homepage:
• Size: 43.9 KB
• Stars: 710
• Watchers: 8
• Forks: 114
• Open Issues: 47
• Metadata Files:
  • Readme: README.rst
  • Changelog: ChangeLog
  • License: LICENSE
  • Authors: AUTHORS

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• starred-awesome - retry - easy to use retry decorator in python (Python)

README

        
retry

=====

.. image:: https://img.shields.io/pypi/dm/retry.svg?maxAge=2592000

        :target: https://pypi.python.org/pypi/retry/

.. image:: https://img.shields.io/pypi/v/retry.svg?maxAge=2592000

        :target: https://pypi.python.org/pypi/retry/

.. image:: https://img.shields.io/pypi/l/retry.svg?maxAge=2592000

        :target: https://pypi.python.org/pypi/retry/

Easy to use retry decorator.

Features

--------

- No external dependency (stdlib only).

- (Optionally) Preserve function signatures (`pip install decorator`).

- Original traceback, easy to debug.

Installation

------------

.. code-block:: bash

    $ pip install retry

API

---

retry decorator

^^^^^^^^^^^^^^^

.. code:: python

    def retry(exceptions=Exception, tries=-1, delay=0, max_delay=None, backoff=1, jitter=0, logger=logging_logger):

        """Return a retry decorator.

        :param exceptions: an exception or a tuple of exceptions to catch. default: Exception.

        :param tries: the maximum number of attempts. default: -1 (infinite).

        :param delay: initial delay between attempts. default: 0.

        :param max_delay: the maximum value of delay. default: None (no limit).

        :param backoff: multiplier applied to delay between attempts. default: 1 (no backoff).

        :param jitter: extra seconds added to delay between attempts. default: 0.

                       fixed if a number, random if a range tuple (min, max)

        :param logger: logger.warning(fmt, error, delay) will be called on failed attempts.

                       default: retry.logging_logger. if None, logging is disabled.

        """

Various retrying logic can be achieved by combination of arguments.

Examples

""""""""

.. code:: python

    from retry import retry

.. code:: python

    @retry()

    def make_trouble():

        '''Retry until succeed'''

.. code:: python

    @retry(ZeroDivisionError, tries=3, delay=2)

    def make_trouble():

        '''Retry on ZeroDivisionError, raise error after 3 attempts, sleep 2 seconds between attempts.'''

.. code:: python

    @retry((ValueError, TypeError), delay=1, backoff=2)

    def make_trouble():

        '''Retry on ValueError or TypeError, sleep 1, 2, 4, 8, ... seconds between attempts.'''

.. code:: python

    @retry((ValueError, TypeError), delay=1, backoff=2, max_delay=4)

    def make_trouble():

        '''Retry on ValueError or TypeError, sleep 1, 2, 4, 4, ... seconds between attempts.'''

.. code:: python

    @retry(ValueError, delay=1, jitter=1)

    def make_trouble():

        '''Retry on ValueError, sleep 1, 2, 3, 4, ... seconds between attempts.'''

.. code:: python

    # If you enable logging, you can get warnings like 'ValueError, retrying in

    # 1 seconds'

    if __name__ == '__main__':

        import logging

        logging.basicConfig()

        make_trouble()

retry_call

^^^^^^^^^^

.. code:: python

    def retry_call(f, fargs=None, fkwargs=None, exceptions=Exception, tries=-1, delay=0, max_delay=None, backoff=1,

                   jitter=0,

                   logger=logging_logger):

        """

        Calls a function and re-executes it if it failed.

        :param f: the function to execute.

        :param fargs: the positional arguments of the function to execute.

        :param fkwargs: the named arguments of the function to execute.

        :param exceptions: an exception or a tuple of exceptions to catch. default: Exception.

        :param tries: the maximum number of attempts. default: -1 (infinite).

        :param delay: initial delay between attempts. default: 0.

        :param max_delay: the maximum value of delay. default: None (no limit).

        :param backoff: multiplier applied to delay between attempts. default: 1 (no backoff).

        :param jitter: extra seconds added to delay between attempts. default: 0.

                       fixed if a number, random if a range tuple (min, max)

        :param logger: logger.warning(fmt, error, delay) will be called on failed attempts.

                       default: retry.logging_logger. if None, logging is disabled.

        :returns: the result of the f function.

        """

This is very similar to the decorator, except that it takes a function and its arguments as parameters. The use case behind it is to be able to dynamically adjust the retry arguments.

.. code:: python

    import requests

    from retry.api import retry_call

    def make_trouble(service, info=None):

        if not info:

            info = ''

        r = requests.get(service + info)

        return r.text

    def what_is_my_ip(approach=None):

        if approach == "optimistic":

            tries = 1

        elif approach == "conservative":

            tries = 3

        else:

            # skeptical

            tries = -1

        result = retry_call(make_trouble, fargs=["http://ipinfo.io/"], fkwargs={"info": "ip"}, tries=tries)

        print(result)

    what_is_my_ip("conservative")