mocker.patch on function

[ulyssejdv]

Hi,
When I want to mock a function in a module, the mock not work if I use this syntax :

from mypkg.mymodule import myfunction

• myfunction()

but work with this one :

from mypkg import mymodule
+mymodule.myfunction()

Any idea ?

[nicoddemus]

@ulyssejdv that is related to how mock works. There's a good explanation here.

I'm closing this for now but feel free to follow up with further questions. 👍

[kaldown]

Just wonder.
If there any way to patch by definition, in a case where the function being imported relatively?

[nicoddemus]

Mocking works by replacing the attribute, so if a module already imported a function, it already has a reference to it, changing the original reference doesn't work.

I guess it might be possible to change the actual function object instead of changing the reference, but they are immutable on the Python side and might require a C extension. However I definitely wouldn't go down that route. 😁