Strange output

[kintarowonders]

I am writing a method and it outputs unexpected results. It is supposed to break up some strings and create lists from them. Yet the lists don't contain everything I expected.

Here is my code:

def get_group_users():
    f = open('group.example', 'r')          #f is file

    users = []                              #obvious
    for l in f:                                     
        g = l.split(':')                    #g is group
        if (g[0] == "users"):
            for ul in g[3]:                 #ul is userline
                gu = ul.split(',')          #gu is groupuser
                for u in gu:                #u is user
                    users.append(u)

    return users

This is the group.example file...

users:x:100:kintaro,john,autossh,test
portage:x:250:portage

This is the output which I did not expect...

>>> import shadowssh
>>> shadowssh.get_group_users()
['k', 'i', 'n', 't', 'a', 'r', 'o', '', '', 'j', 'o', 'h', 'n', '', '', 'a', 'u', 't', 'o', 's', 's', 'h', '', '', 't', 'e', 's', 't', '\n']

The output I want...

['kintaro', 'john', 'autossh', 'test']