groupby in python

>>> n_by_state = df.groupby("state")["state"].count()
>>> n_by_state.head(10)
state
AK     16
AL    206
AR    117
AS      2
AZ     48
CA    361
CO     90
CT    240
DC      2
DE     97
Name: last_name, dtype: int64

>>> df = pd.DataFrame({'col_1': ['value_1', 'value_2',
...                               'value_3', 'value_4'],
...                    'col_2': [value_1, value_2, value_3, value_4]})
>>> df

>>> df.groupby(['column_name']).mean()
     
new_df = pd.DataFrame(df.groupby(['col_1'])['col_2'].count())

# applying groupby() function to 
# group the data on team value. 
gk = df.groupby('Team') 
  
# Let's print the first entries 
# in all the groups formed. 
gk.first()