Freezegun is a Python library designed to freeze time during code execution, great for testing time-dependent functionality.
Its primary utility lies in mocking the current time returned by Python’s datetime.datetime.now() and related functions.
By freezing time, Freezegun enables you to simulate various points in time without affecting the actual advancement of the system clock.
pip install freezegun
from freezegun import freeze_time
def get_greeting():
current_time = datetime.now()
if current_time.hour < 12:
return “Good morning!”
elif 12 ⇐ current_time.hour < 18:
return “Good afternoon!”
else:
return “Good evening!”
# Test case with frozen time using freezegun
@freeze_time(“2023-01-01 12:00:00”)
def test_get_greeting_frozen_time():
# This test will always use the frozen time, so the result is predictable
greeting = get_greeting()
assert greeting == “Good afternoon!”