groupby datetime year-month only

Question

I need to groupby based on the year & month of the Date column so I have a clearer graph presentation and less sample-size.

 
df.groupby(df2['Date'])['¢/kWh'].mean() 

This has helped me to have less sample size and a better presentation. However I need to further groupby based on the month and year.

Answer 1

Try:

df.groupby(df2['Date'].astype(str).str[0:7])['¢/kWh'].mean()