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Waiting, for humans.

Project description

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Build Status codecov Code style: black License: MIT image image

W8ing is (as the great Kenneth Reitz would say) waiting and or polling for humans.

Get it? The 8 replaces the a in waiting :wink: :woman_shrugging:.

Let W8ing help you nuke all your hard calls to time.sleep() and make your tests less flakey :metal:.


Install via pip (highly recommend installing within a Pipenv):

pip3 install w8ing


Wait until some condition is true:

from w8ing import wait

# This example uses an imaginary function that doesn't immediately give us the value we want.
result = wait.until(condition=lambda: get_cat_treats(8) == 8)

# By default, this wait will return whether or not the condition was true or not.

Wait until an http request is valid:

import requests
from w8ing import wait

# You can even specify the timeout and retry delay.
response = wait.until(lambda: requests.get(""), retry_time=1, timeout=15)

# By default a successful response (codes 2XX) object is truthy.
<Response [200]>

Wait until a serial device becomes available and catch any associated exceptions (for you hardware people):

import serial
from w8ing import wait

# If successful, you'll get a pyserial object back, otherwise you'll get None!
serial_port = wait.until(
    lambda: serial.Serial('/dev/ttyUSB0'), catch_exceptions=(SerialException,), retry_time=1, timeout=30

# If it doesn't open you can make a nice assert so your co-workers love you.
assert serial_port, "Unable to open serial port! Did you even plug it in??"

# Otherwise, continue!
"boots and cats"

You can also call another function each loop!

from w8ing import wait

cat_treats = []

# The call_each_try function gets called each time the condition gets evaluated, 
result = wait.until(lambda: len(cat_treats) > 8, call_each_try=lambda: cat_treats.append("treat"), retry_time=0.5)

# The cat will be pleased.

But wait, there's more!

What if you need to ensure that some condition remains true?? Got you covered fam:

from w8ing import wait

cat_nip = ["cat nip"] * 10
result = wait.ensure(lambda: len(cat_nip) > 5, call_each_try=lambda: cat_nip.pop(), retry_time=1, timeout=2)


# The cat will extra intoxicated by this high quality cat nip, good job.


Feel free to open an issue and once you get a green light, submit a PR!

All PRs will receive respectful and constructive feedback.

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