Updated process_report.py to avoid warnings for SettingWithCopyWarnings and FutureWarnings

[QuanMPhm]

Closes #34, I've added a few small changes which should remove all pandas SettingWithCopyWarning and FutureWarning warnings. These consisted of explicit type casting, and explicitly making copies of data-frames that would later be modified

[larsks]

I'm not sure I understand the relationship between the title of this PR ("Patched pandas warnings for SettingWithCopyWarnings and FutureWarnings") and the changes it contains.

[QuanMPhm]

@larsks Without the changes, running the processing script will make Pandas print the 2 warnings mentioned in the title. The SettingWithCopyWarnings came from the fact that I was performing chained indexing on a few dataframes. Since chained indexing may return a copy of the dataframe or dataframe itself, this causes ambiguity on whether assignments to the indexed dataframes would change the original, or merely a copy. I resolved the warnings by explicitly using the copy() function to make copies of the dataframes.

As for the FutureWarnings, these were caused by assigning strings to empty columns, whose values default to NaN (float). Since float is incompatible with strings, this raises a warning.

[larsks]

Ah, so "Update code to avoid SettingWithCopyWarnings and FutureWarnings".

[naved001]

Without the changes, running the processing script will make Pandas print the 2 warnings mentioned in the title. The SettingWithCopyWarnings came from the fact that I was performing chained indexing on a few dataframes. Since chained indexing may return a copy of the dataframe or dataframe itself, this causes ambiguity on whether assignments to the indexed dataframes would change the original, or merely a copy. I resolved the warnings by explicitly using the copy() function to make copies of the dataframes.

As for the FutureWarnings, these were caused by assigning strings to empty columns, whose values default to NaN (float). Since float is incompatible with strings, this raises a warning.

@QuanMPhm You should probably put that into the commit message because it is a good explanation of what's going on.

[QuanMPhm]

@naved001 I've updated the commit message