Imu Imu - 2 months ago 17
Python Question

Take column of string data in pandas dataframe and split into separate columns

I have a pandas dataframe from data I read from a CSV. One column is for the name of a group, while the other column contains a string (that looks like a list), like the following:

Group | Followers
------------------------------------------
biebers | u'user1', u'user2', u'user3'
catladies | u'user4', u'user5'
bkworms | u'user6', u'user7'


I'd like to try to split up the strings in the "Followers" column and make a separate dataframe where each row is for a user, as well as a column showing which group they're in. So for this example I'd like to get the following:

User | Group
--------------------------------
user1 | biebers
user2 | biebers
user3 | biebers
user4 | catladies
user5 | catladies
user6 | bkworms
user7 | bkworms


Anyone have suggestions for the best way to approach this? Here's a screenshot of what it looks like:

enter image description here

Answer
df.Followers = df.Followers.str.replace(r"u'([^']*)'", r'\1')

df.set_index('Group').Followers.str.split(r',\s*', expand=True) \
  .stack().rename('User').reset_index('Group').set_index('User')

enter image description here


To keep User as a column.

df.Followers = df.Followers.str.replace(r"u'([^']*)'", r'\1')

df.set_index('Group').Followers.str.split(r',\s*', expand=True) \
  .stack().rename('User').reset_index('Group') \
  .reset_index(drop=True)[['User', 'Group']]
Comments