export to csv based on column values in pandas

Question

i have a df like this

user = pd.DataFrame({'User':['101','101','101','102','102','101','101','102','102','102'],'Country':['India','Japan','India','Brazil','Japan','UK','Austria','Japan','Singapore','UK'],'Count':[50,1,2,5,6,89,10.9,10,5,6]})

and exporting each user data into seperate csv file like this

user_101 = user[user['User'] == '101']
user_102 = user[user['User'] == '102']

user_101.to_csv('user_101.csv',sep=',')
user_102.to_csv('user_102.csv',sep=',')

how to automate this instead of manually passing the userid's automatically picks the values from User column and export to respective user name files. Thanks

Answer 1

Using a for loop with groupby and f-strings (Python 3.6+):

for user_id, group in user.groupby('User'):
    group.to_csv(f'user_{user_id}.csv', sep=',')

Answer 2

You can loop over unique values of User:

import pandas as pd

user = pd.DataFrame({'User':['101','101','101','102','102','101','101','102','102','102'],'Country':['India','Japan','India','Brazil','Japan','UK','Austria','Japan','Singapore','UK'],'Count':[50,1,2,5,6,89,10.9,10,5,6]})

for u in user['User'].unique():
    file_name = 'user_{0}.csv'.format(u) 
    user[user['User'] == u].to_csv(file_name, sep=',')