Python Retries

retries.py

import time

# testing out the retry pattern described here:
# https://stackoverflow.com/questions/2083987/how-to-retry-after-exception/2083996#2083996

tries = 5
sleep = 1

def throw_exception():
  return '2' + 2

##########################################

print("\nTest case: complete failure\n")

for attempt in range(tries):
  try:
    print(f'Trying {attempt}...')
    throw_exception()
  except:
    print('Failure, sleeping...')
    time.sleep(sleep)
  else:
    print('Success, moving on!')
    break
else:
  print(f'We failed all {tries} tries')

##########################################

print("\nTest case: works on first try\n")

for attempt in range(tries):
  try:
    print(f'Trying {attempt}...')
  except:
    print('Failure, sleeping...')
    time.sleep(sleep)
  else:
    print('Success, moving on!')
    break
else:
  print(f'We failed all {tries} tries')

##########################################

print("\nTest case: eventually works\n")

for attempt in range(tries):
  try:
    print(f'Trying {attempt}...')
    if attempt < 2:
      throw_exception()
  except:
    print('Failure, sleeping...')
    time.sleep(sleep)
  else:
    print('Success, moving on!')
    break
else:
  print(f'We failed all {tries} tries')