egg-timer 1.3.0

A simpler way to handle timeouts in Python

EggTimer

There are some ubiquitous patterns that are elegant and simple. There are others that are not.

Common Solution

from time import time, sleep

max_sleep_time_sec = 1.5

start_time = time()
timeout_sec = 42.0

while time() - start_time < timeout_sec:
    # Do or check some stuff

    time_remaining = timeout_sec - (time() - start_time)
    if time_remaining > max_slep_time_sec:
        sleep(min(time_remaining, max_sleep_time_sec))
    else:
        sleep(max_sleep_time_sec)

What is the purpose of this loop? Oh, I see, it's a timeout. Is the order of operations correct in my loop condition? Have I correctly calculated time_remaining? Is my if clause correct? Hint: It's not. Does this code behave properly if the system clock is updated after I set start_time? Hint: It doesn't. How many times is this code duplicated within my application?

We can do better. EggTimer can help.

EggTimer Example

from time import sleep

from eggtimer import EggTimer

max_sleep_time_sec = 1.5

timer = EggTimer()
timer.set(42.0)

while not timer.is_expired():
    # Do or check some stuff

    sleep(min(timer.time_remaining_sec, max_sleep_time_sec))

Ah, that's better! Clear, concise, reusable, and expressive. The risk of defects is significantly lower, too!

Installation

Install with pip install -U egg-timer

Documentation

Classes

EggTimer - A class for checking whether or not a certain amount of time has elapsed.

ThreadSafeEggTimer - A thread-safe implementation of EggTimer.

See EggTimer Example for an example of how to use EggTime. ThreadSafeEggTimer shares the same interface.

Class documentation

Python 3.10.4 (main, Jun 29 2022, 12:14:53) [GCC 11.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from eggtimer import EggTimer
>>> help(EggTimer)
Help on class EggTimer in module eggtimer.eggtimer:

class EggTimer(builtins.object)
 |  A class for checking whether or not a certain amount of time has elapsed.
 |
 |  Methods defined here:
 |
 |  __init__(self)
 |      Initialize self.  See help(type(self)) for accurate signature.
 |
 |  is_expired(self)
 |      Check whether or not the timer has expired
 |
 |      :return: True if the elapsed time since set(TIMEOUT_SEC) was called is greater than
 |               TIMEOUT_SEC, False otherwise
 |
 |  reset(self)
 |      Reset the timer without changing the timeout
 |
 |  set(self, timeout_sec: float)
 |      Set a timer
 |
 |      :param timeout_sec: A non-negative floating point number expressing the number of
 |                          seconds to set the timeout for.
 |
 |  ----------------------------------------------------------------------
 |  Readonly properties defined here:
 |
 |  time_remaining_sec
 |      Return the amount of time remaining until the timer expires.
 |
 |      :return: The number of seconds until the timer expires. If the timer is expired, this
 |               function returns 0 (it will never return a negative number).
 |
 |  ----------------------------------------------------------------------
 |  Data descriptors defined here:
 |
 |  __dict__
 |      dictionary for instance variables (if defined)
 |
 |  __weakref__
 |      list of weak references to the object (if defined)

>>>

Running the tests

Running the tests is as simple as poetry install && poetry run pytest

License

EggTimer is open-source software licensed under the GNU General Public License v3.0.