FreezeGun: easy mocking of Python datetimes (opens in new tab)

(stevepulec.com)

88 pointsspulec13y ago16 comments

16 comments

14 comments · 7 top-level

JonnieCache13y ago· 3 in thread

Rubyists desiring similar functionality should check out either of the following libs. As far as I can tell they differ only in their pun selection.

https://github.com/travisjeffery/timecop

https://github.com/bebanjo/delorean

In the ruby community, disliking someone's choice of science fiction reference is grounds for a rewrite.

aidenn013y ago

So I need to write one called "tardis"?

indiecore13y ago

>In the ruby community, disliking someone's choice of science fiction reference is grounds for a rewrite.

Hmm, perhaps I should check Ruby out after all...

phillmv13y ago

It's great. We got unicorns and Series As for everyone!

TimothyFitz13y ago· 2 in thread

Cool, but unfortunately it breaks if the code your testing does from datetime import datetime :(

https://gist.github.com/4261936

spulecOP13y ago

Hey Timothy, thanks for the response. You are correct. I'll add a warning to the library and work on a solution. Unfortunately, I think it will need to involve ctypes.

subleq13y ago

Have you tried patching the now() method onto datetime.datetime instead of replacing the whole class? If that doesn't work, you could replace datetime first:

    import freezegun; freezegun.monkey_patch()
    from datetime import datetime

After that, freeze_time would just set a flag on your datetime class.

1 more reply

ericmoritz13y ago· 1 in thread

nice project. I usually avoid this by making my APIs accept a datetime objects and make the client code create the datetime object.

Pure functions make tests simple.

new_test13y ago

That's what I've been doing, but not because I believe it to be a better way, but because I'm to lazy to implement my own FreezeGun. I don't think the production code should contain unnecessary complexity that is only used for testing.

manish_gill13y ago· 1 in thread

I don't really have much experience in datetimes I guess. What is this really good for? Can someone provide some use cases where this library might be helpful?

Thanks

chewxy13y ago

Mainly for testing

marcofucci13y ago

Quick question: why did you need to write FreezeGun?

I've always used Mock http://www.voidspace.org.uk/python/mock/ to patch datetimes and I've never had any problems.

You can patch pretty much anything with Mock.

ekimekim13y ago

What about those of us who prefer the simpler time module (which works mostly in epoch time)? It would be a simple change to extend FreezeGun to cover that module in a similar way, surely?

davepeck13y ago

How well does this handle aware (non-naive) datetimes?

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