BUG: Fixes KeyError when indexes don't overlap.

[tshauck]

Closes #10291

[TomAugspurger]

Can you edit your first post to include "Closes #10291, Closes #12133" so that Github will auto-close those issues when we merge?

Also would need a release note in doc/source/whatsnew/v0.18.0 under bug fixes and maybe add a note to the docstring of crosstab explaining that this is the outcome for non-overlapping indices. Thanks!

[jreback]

construct the actual result and use assert_frame_equal

[jreback]

you need a test to cover #12133

[jreback]

pls add a whatsnew as well

[tshauck]

Thought it may be easier in the near term to reduce the scope of this change to fixing the issue associated with #10291 and not attempt a fix at #12133.

I've added #12133 to my todo list so I'll try to get back to it. Hopefully it's as simple as adding a test case.

[jreback]

thanks @tshauck

[Winand]

if values_passed and not values_multi and not table.empty:
Excuse me, but how does this cover #12133? index names are dropped earlier in if not dropna: block. We need to pass names to from_arrays:

m = MultiIndex.from_arrays(cartesian_product(table.index.levels), names=table.index.names)
...
m = MultiIndex.from_arrays(cartesian_product(table.columns.levels), names=table.columns.names)

UPD: sorry, i thought that it's as simple as adding a test case means that it covers #12133 but tests are needed
UPD2: #12327

[jreback]

if u read the comments about it does not cover 12133