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Metadata-Version: 2.1
Name: redo
Version: 3.0.0
Summary: Utilities to retry Python callables.
Author: Ben Hearsum
Author-email: ben@hearsum.ca
License: MPL-2.0
Classifier: License :: OSI Approved :: Mozilla Public License 2.0 (MPL 2.0)
Classifier: Programming Language :: Python :: 3.8
Classifier: Programming Language :: Python :: 3.9
Classifier: Programming Language :: Python :: 3.10
Classifier: Programming Language :: Python :: 3.11
Classifier: Programming Language :: Python :: 3.12
License-File: LICENSE
License-File: AUTHORS
Redo - Utilities to retry Python callables
==========================================
Introduction
************
Redo provides various means to add seamless ability to retry to any Python callable. Redo includes plain functions (``redo.retry``, ``redo.retry_async``), decorators (``redo.retriable``, ``redo.retriable_async``), and a context manager (``redo.retrying``) to enable you to integrate it in the best possible way for your project. As a bonus, a standalone interface is also included (``"retry"``).
Installation
************
For installing with pip, run following commands
::
pip install redo
How To Use
**********
Below is the list of functions available
* retrier
* retry
* retry_async
* retriable
* retriable_async
* retrying (contextmanager)
retrier(attempts=5, sleeptime=10, max_sleeptime=300, sleepscale=1.5, jitter=1)
------------------------------------------------------------------------------
A generator function that sleeps between retries, handles exponential back off and jitter. The action you are retrying is meant to run after retrier yields. At each iteration, we sleep for ``sleeptime + random.randint(-jitter, jitter)``. Afterwards sleeptime is multiplied by sleepscale for the next iteration.
**Arguments Detail:**
1. **attempts (int):** maximum number of times to try; defaults to 5
2. **sleeptime (float):** how many seconds to sleep between tries; defaults to 60s (one minute)
3. **max_sleeptime (float):** the longest we'll sleep, in seconds; defaults to 300s (five minutes)
4. **sleepscale (float):** how much to multiply the sleep time by each iteration; defaults to 1.5
5. **jitter (int):** random jitter to introduce to sleep time each iteration. the amount is chosen at random between ``[-jitter, +jitter]`` defaults to 1
**Output:** None, a maximum of ``attempts`` number of times
**Example:**
::
>>> n = 0
>>> for _ in retrier(sleeptime=0, jitter=0):
... if n == 3:
... # We did the thing!
... break
... n += 1
>>> n
3
>>> n = 0
>>> for _ in retrier(sleeptime=0, jitter=0):
... if n == 6:
... # We did the thing!
... break
... n += 1
... else:
... print("max tries hit")
max tries hit
retry(action, attempts=5, sleeptime=60, max_sleeptime=5 * 60, sleepscale=1.5, jitter=1, retry_exceptions=(Exception,), cleanup=None, args=(), kwargs={})
--------------------------------------------------------------------------------------------------------------------------------------------------------
Calls an action function until it succeeds, or we give up.
**Arguments Detail:**
1. **action (callable):** the function to retry
2. **attempts (int):** maximum number of times to try; defaults to 5
3. **sleeptime (float):** how many seconds to sleep between tries; defaults to 60s (one minute)
4. **max_sleeptime (float):** the longest we'll sleep, in seconds; defaults to 300s (five minutes)
5. **sleepscale (float):** how much to multiply the sleep time by each iteration; defaults to 1.5
6. **jitter (int):** random jitter to introduce to sleep time each iteration. The amount is chosen at random between ``[-jitter, +jitter]`` defaults to 1
7. **retry_exceptions (tuple):** tuple of exceptions to be caught. If other exceptions are raised by ``action()``, then these are immediately re-raised to the caller.
8. **cleanup (callable):** optional; called if one of ``retry_exceptions`` is caught. No arguments are passed to the cleanup function; if your cleanup requires arguments, consider using ``functools.partial`` or a ``lambda`` function.
9. **args (tuple):** positional arguments to call ``action`` with
10. **kwargs (dict):** keyword arguments to call ``action`` with
**Output:** Whatever action(\*args, \*\*kwargs) returns
**Output:** Whatever action(\*args, \*\*kwargs) raises. ``retry_exceptions`` are caught up until the last attempt, in which case they are re-raised.
**Example:**
::
>>> count = 0
>>> def foo():
... global count
... count += 1
... print(count)
... if count < 3:
... raise ValueError("count is too small!")
... return "success!"
>>> retry(foo, sleeptime=0, jitter=0)
1
2
3
'success!'
retry_async(func, attempts=5, sleeptime_callback=calculate_sleep_time, retry_exceptions=Exception, args=(), kwargs={}, sleeptime_kwargs=None)
---------------------------------------------------------------------------------------------------------------------------------------------
An asynchronous function that retries a given async callable.
**Arguments Detail:**
1. **func (function):** an awaitable function to retry
2. **attempts (int):** maximum number of attempts; defaults to 5
3. **sleeptime_callback (function):** function to determine sleep time after each attempt; defaults to `calculateSleepTime`
4. **retry_exceptions (list or exception):** exceptions to retry on; defaults to `Exception`
5. **args (list):** arguments to pass to `func`
6. **kwargs (dict):** keyword arguments to pass to `func`
7. **sleeptime_kwargs (dict):** keyword arguments to pass to `sleeptime_callback`
**Output:** The value from a successful `func` call or raises an exception after exceeding attempts.
**Example:**
::
>>> async def async_action():
... # Your async code here
>>> result = await retry_async(async_action)
retriable(\*retry_args, \*\*retry_kwargs)
-----------------------------------------
A decorator factory for ``retry()``. Wrap your function in ``@retriable(...)`` to give it retry powers!
**Arguments Detail:** Same as for ``retry``, with the exception of ``action``, ``args``, and ``kwargs``, which are left to the normal function definition.
**Output:** A function decorator
**Example:**
::
>>> count = 0
>>> @retriable(sleeptime=0, jitter=0)
... def foo():
... global count
... count += 1
... print(count)
... if count < 3:
... raise ValueError("count too small")
... return "success!"
>>> foo()
1
2
3
'success!'
retriable_async(retry_exceptions=Exception, sleeptime_kwargs=None)
------------------------------------------------------------------
A decorator for asynchronously retrying a function.
**Arguments Detail:**
1. **retry_exceptions (list or exception):** exceptions to retry on; defaults to `Exception`
2. **sleeptime_kwargs (dict):** keyword arguments to pass to the sleeptime callback
**Output:** A function decorator that applies `retry_async` to the decorated function.
**Example:**
::
>>> @retriable_async()
... async def async_action():
... # Your async code here
>>> result = await async_action()
retrying(func, \*retry_args, \*\*retry_kwargs)
----------------------------------------------
A context manager for wrapping functions with retry functionality.
**Arguments Detail:**
1. **func (callable):** the function to wrap other arguments as per ``retry``
**Output:** A context manager that returns ``retriable(func)`` on ``__enter__``
**Example:**
::
>>> count = 0
>>> def foo():
... global count
... count += 1
... print(count)
... if count < 3:
... raise ValueError("count too small")
... return "success!"
>>> with retrying(foo, sleeptime=0, jitter=0) as f:
... f()
1
2
3
'success!'