How to pass parameters to the innermost function when i use python decorator with parameters? [duplicate]

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here is my decorator for recall func when func return is not True

def deco_retry(retry_times):
def _deco_retry(func):
def wrapper(*args, **kwargs):
while retry_times > 0:
ret = func(*args, **kwargs)
if ret:
return ret
retry_times -= 1
return wrapper
return _deco_retry

@deco_retry(retry_times=1)
def func(ok=1):
if ok == 1:
return True
else:
return False


when i call func(), error occurred:

Traceback (most recent call last):
File "E:/Charles/Code/pycharmprj/Huobi/test_code/decorator_test.py", line 26, in <module>
func()
File "E:/Charles/Code/pycharmprj/Huobi/test_code/decorator_test.py", line 10, in wrapper
while retry_times > 0:
UnboundLocalError: local variable 'retry_times' referenced before assignment


why can't i reference retry_times in the innermost function: wrapper, how can i correct this error?

retry_times

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1 Answer
1

This is because you are re-assigning retry_times later in the function with retry_times -= 1, hence making it a local variable.

retry_times

retry_times -= 1

You can add nonlocal (if python3) right above the while loop:

nonlocal

def _deco_retry(func):
def wrapper(*args, **kwargs):
nonlocal retry_times
while retry_times > 0:


Or instead of using a while loop, you can try looping with range instead:

while

range

def wrapper(*args, **kwargs):
for _ in range(retry_times):
ret = func(*args, **kwargs)
if ret:
return ret


Should work the same, and you don't have to mess around with adding/subtracting the amount of retries.