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pythonindexingkeyerrordatetimeindex

KeyError using Index

Apologies for the fairly basic question.

Basically I have a large dataframe where I'm pulling out the top dates for the sum of certain values. Looks like this:

hv_toploss = hv.groupby(['END_VALID_DT']).sum()
hv_toploss=hv_toploss.sort_values('TOTALPL',ascending=False).iloc[:10]
hv_toploss['END_VALID_DT'] = pd.to_datetime(hv_toploss['END_VALID_DT'])

Now, END_VALID_DT becomes the index of hv_toploss, and I get a KeyError when running line 3. If I try to reindex, I get a multi-index error, and since these are the values I need, I can't just drop the index.

I will be calling these values in a line like:

PnlByDay = PnlByDay.loc[hv_toploss['END_VALID_DT']]

Any help here would be great. I'm still a novice using Python.

Solution

  • You can use the index directly instead of creating another column containing the index. 

    the_dates = hv_toploss.sort_values('TOTALPL',ascending=False).iloc[:10].index
PnlByDay.loc[PnlByDay.index.isin(the_dates)]

    I don't know the structure of PnlByDay, so you may have to modify that part.