groupby count pandas example

Example 1: group by count dataframe

df.groupby(['col1', 'col2']).size().reset_index(name='counts')

Example 2: pandas count values by column

df = pd.DataFrame({'a':list('abssbab')})
df.groupby('a').count()

Example 3: pandas count

>>> df.set_index(["Person", "Single"]).count(level="Person")
        Age
Person
John      2
Lewis     1
Myla      1