Inconsistency in crossmatch column data types

[camposandro]

Bug report

If we decide to keep the non-matches it's possible to get NaN values in our crossmatch dataframe. For every point in the left partitions we will have a row with the left point information and the information of the respective match on the right (which being inexistent will be set to NaN).

When assigning a row with NaN values on a dataframe, Pandas seems to automatically cast the whole column type to "float". Columns such as Norder_{}_xmatch, Dir_{}_xmatch and Npix_{}_xmatch, therefore have an incorrect type.

We should create an end-to-end test to verify that the column data types of the original catalogs remain unchanged.

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[delucchi-cmu]

Has this been addressed (or a little bit improved) by the pyarrow dtype changes?

[camposandro]

@delucchi-cmu yes, supporting None values by default using pyarrow should fix the column types. We're holding off on the merge of #271 this week but I might try to build some end-to-end tests in the meantime to make sure the output columns of the crossmatch indeed remain the same!

[delucchi-cmu]

This has been addressed by recent changes to using pyarrow types, and holding on to the pyarrow schema throughout operations.

[camposandro]

We should make sure the Dask DataFrame meta and the pyarrow schema are consistent whenever we address #390.