Python Timeout Library
This is the source for the timeoutlib python library.
The library solves the following problem: given a computational budget in seconds, and a function that performs some work, ensure that the computation does not take longer than the budgeted duration
In the event that a function times out, you can choose to return a default value, raise an exception or return a default
from a default_factory.
Usage
You can use a decorator or functional syntax to wrap your function
import time
import timeoutlib
# Decorator syntax
# will raise timeoutlib.OperationTimedOut if 5s exceeded
@timeoutlib.timeout(max_duration=5)
def worker(simulated_duration):
time.sleep(simulated_duration)
# will return False if 5s exceeded
@timeoutlib.timeout(max_duration=5, default=False)
def worker_default_value(simulated_duration):
time.sleep(simulated_duration)
return True
# will call list() to return a new empty list as a default value if 5s exceeded
@timeoutlib.timeout(max_duration=5, default_factory=list)
def worker_default_value(simulated_duration):
time.sleep(simulated_duration)
return True
# will raise a RuntimeError if 5s exceeded
@timeoutlib.timeout(max_duration=5, exception=RuntimeError)
def worker_default_value(simulated_duration):
time.sleep(simulated_duration)
return True
# The two alternative syntax below are equal
@timeoutlib.timeout(max_duration=2)
def worker_decorator(simulated_duration):
time.sleep(simulated_duration)
return True
# Given some function that you want to decorate dynamically
def worker_functional(simulated_duration):
time.sleep(simulated_duration)
return True
worker_functional = timeoutlib.timeout(max_duration=2)(worker_functional)
# worker_functional and worker_decorated behave the sameCaveats / Notes
- Only supports integer durations (no fractional seconds)
- Uses SIGALRM under the hood (unix only - will not work on Windows)
-
timeoutlib.OperationTimedOutsubclasses the builtin TimeoutError - The default_factory assumes a function with zero args that returns a new default value
- Accuracy of the timeout duration depends on the underlying OS, Hardware, and some overhead from the decorator itself.
