df.groupby('client_id')[['client_id']].count()
df.client_id.value_counts()
df.client_id.value_counts().to_frame(name='count')
new_df.index.name = 'my_index'
new_df.columns = ['count']
df.groupby('client_id')[['client_id']].count().rename(columns=
{'client_id':'Ид_Клиента'})