Added debug kwarg

decorate.py

def exponential_backoff(exception, err=None, tries=5, debug=False):
    """Exponentially backoff on a certain Exception exception.
    params:
        tries - num of expn backed off attempts before quitting
        err - custom error msg to display in addition to 'e'
        debug - default False, boolean deciding whether to raise
                error msg e along with Exception instance
    
    note:                                                                       
        * debug flag used to avoid raising security sensitive exception err msgs
        * sleep may be unsafe (hence adding a psuedo random
          scalar, still bad since not really random)                                                                               
        * Consider logging errors via http://pypi.python.org/pypi/sentry 

    usage:                                                                                                                                             
    >>> @exponential_backoff(SomeNetworkError, tries=2)
    ... def foo(bar):
    ...     transfer_file(bar)
    SomeNetworkError: [ExponentialBackoff] Timed out
    after 2 attempts. Network failed to connect. (details: None)
    """
    def decorator(func):
        def inner(*args, **kwargs):
            for n in range(0, tries):
                try:
                    return func(*args, **kwargs)
                except exception as e:
                    scalar = random.randint(0, 1000) / 1000.0
                    time.sleep((2 ** n) + scalar)
            e = e if debug else ''
            raise exception('[Exponential Backoff] ' \
                                'Timed out after %s attempts. ' \
                                '%s (details: %s)' % (tries, e, err))
        return inner
    return decorator

Originally authored this as anonymous, accidentally. Forking back to keep track of it.