Sometimes we want a function to be able to be retried automatically, such as a function that does networking trying to write/read data through a pre-established connection. Instead of writing try/except everywhere, a decorator would save much code and provide a single copy of code to do all the work.
Python, 35 lines
Download
Copy to clipboard1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 | def conditional_retry(func=None, exceptions=Exception,
action=None, callback_args=(), timeout=2):
'''
This decorator is able to be called with arguments.
:keyword exceptions: exceptions in a tuple that will be
tested in the try/except
:keyword action: a callable to be called at the end of every
time of re-attempt
:keyword callback_args: arguments to be passed into the callable
:keyword timeout: times of attempt, defaults to 2
'''
def decorated(func):
def wrapper(*args, **kwargs):
result = None
i = 1
while i <= timeout:
try:
result = func(*args, **kwargs)
break
except exceptions:
if i == timeout:
raise
if callable(action):
action(*callback_args)
i += 1
return result
return wrapper
if func is None: # in this case, the decorator is called with arguments
def decorator(func):
return decorated(func)
return decorator
# or the decorator is called without arguments
return decorated(func)
|
