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pythonpandasdataframeseries

How to reverse a pandas series

I have a pandas series that must be flipped upside-down before I concatenate it to the main DataFrame.

I can easily flip it with myseries = myseries.iloc[::-1]

But when I attach it to the main DataFrame, it attaches the default series and not the flipped version. Why doesn't the flipped series stay in place?

myseries = myseries.iloc[::-1] 
newdf = pd.concat([newdf, myseries], axis=1)

EDIT: So my guess is that the index is being flipped as well, and when I concatenate its probably using the index to attach the series. Is there a way to flip the values in the series but leave the index untouched? My index starts at 2.

Solution

  • This is occurring because concatenating is based on the index. You can save the original index, and then set the index of the reversed series equal to the original index:

    myseries_index = myseries.index
myseries = myseries.iloc[::-1]
myseries.index = myseries_index