Retry decorator in Python

retry.py

import random
import time

# This is the decorator - it's essentially a function that takes in a function
# as a parameter and returns a modified version of it
def retry(func, max_attempts=4, initial_delay=1):
  def wrapper(*args, **kwargs):
    delay = initial_delay
    attempt = 1
    while True:
      try:
        return func(*args, **kwargs)
      except Exception as e:
        if attempt == max_attempts:
          raise e
        print(e)
        print('Retrying in {} seconds'.format(delay))
        time.sleep(delay)
        delay *= 2
        attempt += 1
  return wrapper

# You can apply a decorator to a function with the @ syntax, this is just sugar
# for calling the decorator function and passing in the original function.
# e.g. you could do
#   fail_half_the_time_with_retry = retry(fail_half_the_time)
# and it would be equivalent
@retry
def fail_half_the_time():
  if random.randint(0, 1) == 0:
    raise Exception('Failed!')
  else:
    return 'Success!'


# now if we call this decoratored version 
print(fail_half_the_time())
# we should seee something like
#   Failed!
#   Retrying in 1 seconds
#   Failed!
#   Retrying in 2 seconds
#   Success!