Can I pass an exception as an argument to a function in python?

decorator, python, python-decorators

Solution

You can supply a `tuple` of exceptions to the `except ..` block to catch:

from functools import wraps

def retry(*exceptions, **params):
    if not exceptions:
        exceptions = (Exception,)
    tries = params.get('tries', 10)

    def decorator(func):
        @wraps(func)
        def wrapper(*args, **kw):
            for i in range(tries):
                try:
                    return func(*args, **kw)
                except exceptions:
                    pass
        return wrapper
    return decorator

The catch-all `*exceptions` parameter will always result in a tuple. I've added a `tries` keyword as well, so you can configure the number of retries too:

@retry(ValueError, TypeError, tries=20)
def foo():
    pass

Demo:

>>> @retry(NameError, tries=3)
... def foo():
...     print 'Futzing the foo!'
...     bar
... 
>>> foo()
Futzing the foo!
Futzing the foo!
Futzing the foo!

Problem

I am new to python. I am trying to create a retry decorator that, when applied to a function, will keep retrying until some criteria is met (for simplicity, say retry 10 times). ``` def retry(): def wrapper(func): for i in range(0,10): try: func() break except: continue return wrapper ``` Now that will retry on any exception. How can I change it such that it retries on specific exceptions. e.g, I want to use it like: ``` @retry(ValueError, AbcError) def myfunc(): //do something ``` I want `myfunc` to be retried only of it throws `ValueError` or `AbcError`.

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