BUG/BLD: pytest not a runtime dep

[chris-b1]

on master - now that we've exposed a testing api, need to wrap the import of pytest

>>> import pandas

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\Chris\Anaconda\envs\py361\lib\site-packages\pandas\__init__.py", line 60, in <module>
    import pandas.testing
  File "C:\Users\Chris\Anaconda\envs\py361\lib\site-packages\pandas\testing.py", line 7, in <module>
    from pandas.util.testing import (
  File "C:\Users\Chris\Anaconda\envs\py361\lib\site-packages\pandas\util\testing.py", line 22, in <module>
    import pytest
ModuleNotFoundError: No module named 'pytest'

[jreback]

actually is there a reason we are doing an import pandas.testing at all in __init__?

@jorisvandenbossche ?

[jorisvandenbossche]

Ah, good catch, but the testing functions do not depend on pytest, so this should be solvable (although maybe a bit annoying to move all imports of pytest inline ..)

actually is there a reason we are doing an import pandas.testing at all in init?

Because otherwise you cannot do pd.testing.assert_frame_equal, but have to explicitly import it (but I can certainly be wrong here!)

[jorisvandenbossche]

Hmm, there is quite a lot of usage of pytest, so inline the import would be very annoying ..

So if you remove the line in init, you get this:

In [1]: pd.testing.assert_frame_equal
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-1-08ffb5740461> in <module>()
----> 1 pd.testing.assert_frame_equal

AttributeError: module 'pandas' has no attribute 'testing'

but have to explicitly import it like from pandas.testing import assert_frame_equal

[jorisvandenbossche]

@jreback do you know how this does work for errors ? (because there directly assessing it does work)

[jreback]

but have to explicitly import it like from pandas.testing import assert_frame_equal

I don't think this is a big deal.

we explicity don't want to import the testings into the main namespace. It could be fixed to isolate, but maybe let's do that later.

[jreback]

@jreback do you know how this does work for errors ? (because there directly assessing it does work)

.errors defines things (or imports from cython libs).

I think we could do this in testing, but it would require hiding the pytest import & lots of other imports (prob not a big deal as they are std lib).