Retrial library for asyncio coroutines

.. image:: https://travis-ci.org/nerandell/async_retrial.svg?branch=master :target: https://travis-ci.org/nerandell/async_retrial

Easy to use retry library based on asyncio_

.. _asyncio: https://docs.python.org/3/library/asyncio.html

Requirements

Python >= 3.3
asyncio https://pypi.python.org/pypi/asyncio

Installation

To install via pip

.. code-block:: bash

$ pip install async_retrial

To install from source

.. code-block:: bash

$ git clone https://github.com/nerandell/async_retrial
$ cd async_retrial
$ python setup.py install

Examples

You can either use RetryHandler or retry decorator

retry decorator

.. code-block:: python

def retry(should_retry_for_result=_default_retry_for_result, 
          should_retry_for_exception=_default_retry_for_exception,
          multiplier=2, timeout=None, max_attempts=None, strategy=None):
            """
    :param should_retry_for_result: A function that is called with argument as result to allow retrial for specific
                                    set of results. Must return a boolean value
    :param should_retry_for_exception: A function that is called if the function to be retried threw an exception 
                                       allow retrial for specific set of exceptions. Must return a boolean value
    :param multiplier: Must be an integer value, If defined, the retrial would be exponential with this behind the 
                       multiplier
    :param timeout: If defined, the function will be retried if no result was returned in this time.
    :param max_attempts: Max number of attempts to retry
    :param strategy: Must be a list of integers. If defined, retrial would follow this strategy. For ex. if strategy 
                     is [1,3,5,8,11], function would be retried at 1, 3, 5, 8, 11, 11, 11, ... seconds
    :return:
    """

To use the decorator:

.. code-block:: python

from retrial.retrial import retry

Using different settings:

.. code-block:: python

@retry()
def my_function(*args, **kwargs):
    '''Retry till successful. Default multiplier is 2'''
    
@retry(multiplier=3)
def my_function(*args, **kwargs):
    '''Retry at 0, 3, 9, 27, 81 ... seconds until successful'''
    
@retry(strategy=[1, 1, 2, 3, 5, 8, 13])
def my_function(*args, **kwargs):
    '''Retry at 1, 1, 2, 3, 5, 8, 13, 13, 13 ... seconds until successful''' 
    
@retry(max_attempts=3)
def my_function(*args, **kwargs):
    '''Retry for a maximum of 3 times'''

@retry(should_retry_for_result=lambda x: x < 0)
def my_function(*args, **kwargs):
    '''Retry if result is negative value'''

@retry(should_retry_for_exception=lambda x: isinstance(x, KeyError))
def my_function(*args, **kwargs):
    '''Retry if exception was of type KeyError'''