group by month pandas code example
Example 1: pandas group by month
b = pd.read_csv('b.dat')
b.index = pd.to_datetime(b['date'],format='%m/%d/%y %I:%M%p')
b.groupby(by=[b.index.month, b.index.year])
b.groupby(pd.Grouper(freq='M'))
df.groupby(pd.TimeGrouper(freq='M'))
Example 2: group by month and day pandas
max_temp = dfall.groupby([(dfall.Date.dt.month),(dfall.Date.dt.day)])['Data_Value'].max()
Example 3: group by 2 columns pandas
In [11]: df.groupby(['col5', 'col2']).size()
Out[11]:
col5 col2
1 A 1
D 3
2 B 2
3 A 3
C 1
4 B 1
5 B 2
6 B 1
dtype: int64