Is There an Easy Way in Python to Wait Until Certain Condition Is True

Is there an easy way in Python to wait until certain condition is true?

Unfortunately the only possibility to meet your constraints is to periodically poll, e.g....:

import time

def wait_until(somepredicate, timeout, period=0.25, *args, **kwargs):
  mustend = time.time() + timeout
  while time.time() < mustend:
    if somepredicate(*args, **kwargs): return True
    time.sleep(period)
  return False

or the like. This can be optimized in several ways if somepredicate can be decomposed (e.g. if it's known to be an and of several clauses, especially if some of the clauses are in turn subject to optimization by being detectable via threading.Events or whatever, etc, etc), but in the general terms you ask for, this inefficient approach is the only way out.

Waiting until the desired condition is met in python

Try this¹:

import time
def list(self):
    command = ["<application_command>", "list"]
    status = False
    start = time.time()
    while True: # while status is false
        status = "running" in self.execute(command)
        if ((time.time() - start) >= 60) and status:
            return
        if status: # if the status is true
            return status
        else:
            continue

_{1: from the ShadowRanger's comment}

Write a Python function that waits and listens until a condition is met, similar to WebDriverWait().until()

This might be difficult to generalise in the way you're thinking about it. Often, you don't want to wait for things. It's better to do other stuff or do nothing. Python has an entire library dedicated to handling this kind of thing. it's called asyncio.

Conceptually, all you need a function that will tell you if some action is complete, and a while loop.

import time    
while not action_is_complete():
    sleep(10)

This will keep going until action_is_complete() returns true. Then your program will continue executing.

How to create a function to wait until a boolean value becomes true

wait_until(lambda: block.distance_to(pygame.mouse.get_pos()) <= 100)

This creates a function that can be called as many times as needed, to evaluate your condition.

Python Asyncio - Pythonic way of waiting until condition satisfied

Using of asyncio.Event is quite straightforward. Sample below.

Note: Event should be created from inside coroutine for correct work.

import asyncio


async def bg_tsk(flag):
    await asyncio.sleep(3)
    flag.set()


async def waiter():
    flag = asyncio.Event()
    asyncio.create_task(bg_tsk(flag))
    await flag.wait()
    print("After waiting")


asyncio.run(waiter())

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