How to (py)test a function that relies on the current time?

Question

I have a function with the following structure.

def foo(*args, **kwargs):
    # ... code
    now = pd.Timestamp('now', tz=0)
    # ... more code
    return result # result depends on "now" variable

I cannot take a timestamp right before or after the execution of foo and use it for comparisons against the return value, because it will differ from the value of now inside the function.

AKX · Accepted Answer · 2021-04-14T06:57:41.317

2

You can use a time mocking library, e. g. https://pypi.org/project/freezegun/ to freeze time to a known instant in your test.

def test_foo():
    with freezegun.freeze_time("2021-04-14"):
        result = foo()  # assert that result is correct for the above date

edited Apr 14 '21 at 06:57

answered Apr 14 '21 at 06:49

AKX

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Thank you. Maybe include a small example in the answer itself? – actual_panda Apr 14 '21 at 06:53
1

Sure. I was on mobile when answering originally, which makes it tedious to write code. Glad I could help! – AKX Apr 14 '21 at 06:58
`freezegun` does not seem to influence `pd.Timestamp('now')`. As a workaround, you can use `pd.Timestamp(datetime.datetime.now())`. – actual_panda Apr 19 '21 at 08:50

How to (py)test a function that relies on the current time?

1 Answers1