Convert Timestamp to_datetime() and aggregate by year and month, Pandas, Python

Question

I have a DF, with timestamps that I converted to datetime(), and I want to create a Python table to aggreagate by month and year, but I get the following error:

ValueError: Duplicated level name: "TimeStamp", assigned to level 1, is already used for level 0 


flowData =pd.read_csv('...')

flowData["TimeStamp"] = pd.to_datetime(flowData["TimeStamp"])

pv = flowData.pivot_table(index=flowData['TimeStamp'].dt.month,columns=flowData['TimeStamp'].dt.year, values='Value', aggfunc=np.mean)
pv.head()

Could you please help me?

Answer 1

Try renaming the indices:

pv = (flowData.pivot_table(index=flowData['TimeStamp'].dt.month.rename('month'),
                           columns=flowData['TimeStamp'].dt.year.rename('year'),
                           values='Value', aggfunc=np.mean))