timelimit

Sets the time limit for slow-running functions. Runs functions in parallel threads or processes.

Tested with Python 3.6-3.9 on macOS, Ubuntu and Windows.

Install

pip3 install timelimit

Use

from timelimit import limit_thread, limit_process, TimeLimitExceeded

def sluggish(a, b):
  ...
  return a + b

# will run sluggish(1, 2) in parallel thread no more than 5 seconds
a_plus_b = limit_thread(sluggish, (1, 2), timeout=5)

# will run sluggish(1, 2) in parallel process no more than 5 seconds
a_plus_b = limit_process(sluggish, (1, 2), timeout=5)

If the time is up

If the function did not complete its work within the specified time, a TimeLimitExceeded exception is thrown.

try:
    limit_thread(sluggish, (1, 2), timeout=5)

except TimeLimitExceeded:
    print("Oops!")  

If you set the default argument (at least to None), the default value is returned instead of an exception.

result = limit_thread(sluggish, (1, 2), timeout=5, default=-1)

if result == -1:
    print("Oops!")

If time doesn't matter

If you do not specify the timeout parameter it will default to float('inf'). The sluggish function will run in a parallel thread or process, but without time constraints.

# both call run the function in parallel thread without time limits
limit_thread(sluggish, (1, 2))  
limit_thread(sluggish, (1, 2), timeout=float('inf')) 

If you specify the value timeout = None, then the sluggish will be executed like a regular function, without starting processes or threads.

# the following calls are equivalent
sluggish(1, 2)
limit_thread(sluggish, (1, 2), timeout=None)

Thus, the limitation can be made optional and resource-saving.

limit_thread(sluggish, (1, 2), 
             timeout = 5 if in_hurry else None)