#datetime #python #dataframe #pandas #pandas-groupby
#python #slice #pandas #pandas-groupby
#python #dataframe #pandas #pandas-groupby
#python #aggregate #standard-deviation #pandas-groupby
#python #pandas #pandas-groupby
#python #aggregate #dataframe #pandas #pandas-groupby
#python-3.x #dataframe #pandas #pandas-groupby
#for-loop #pandas #xlsxwriter #pandas-groupby