Losing data on a Pandas DataFrame reindex

Question

I was losing data on a reindex. I just wanted to make an existing column the index.

So this works:

df_all_maa = df_all_maa.set_index("VERSION_SEQ")

Originally I was doing this:

df_all_maa = df_all_maa.reindex(df_all_maa["VERSION_SEQ"])

I think what was happening was I was only getting values in the resulting dataframe, where the VERSION_SEQ value happened to match the numeric default index, but I would be interested to know what my original incorrect syntax was actually doing.

score 1 · Answer 1 · answered Jul 23 '20 at 13:06

1

reindex is similar to loc, but allowing non-existing indexes. reindex creates a row with nan values whence there are non-existing indexes, while loc would throw an error.

answered Jul 23 '20 at 13:06

Quang Hoang

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thanks for this. I was trying to understand what my statement was actually asking Pandas to do? – smackenzie Jul 23 '20 at 14:26

Losing data on a Pandas DataFrame reindex

1 Answers1