Create CSV file of domain groups and their users I'm fairly new to scripting in Python. I'm looking for suggestions on improving any of the following in the below script: my coding style, performance, readability, commenting, or anything else.

"""
META
Author: James Nicholson
Date: 8/16/2013

DESCRIPTION
This script takes a list of groups from a text file and creates a new text file
in CSV format that contains group members in the below format:

group_name1,user_name1
group_name1,user_name2
etc...

VARIABLES
server = 'domain name'
glist = 'path to text file containing desired groups'
"""

# Import the win32 module needed for accessing groups and members
import win32net

# Set server name and group_list text file variables
server = # enter server name here
group_list = 'groups.txt'
grps = []

# Loop over lines in group_list and store group names in a list
with open(group_list, 'rb') as my_groups:
    for line in my_groups:
        grps.append(line.rstrip('\r\n'))

# Loop over groups and store members in desired format in new text file 'groups_members_output.txt'
with open('groups_members_output.txt', 'wb') as blank_file:
    for group in grps:
        usrs = win32net.NetGroupGetUsers(server,group,0)
        for user in usrs[0]:
            blank_file.write('{},{}\r\n'.format(group,user['name']))
Some notes:


Comments: A lot (if not all) of the comments are pretty much repeating what the code already says. I'd remove them.
server = # enter server name here. Create functions with configurable elements as arguments instead of global variables.
with open('groups_members_output.txt', 'wb') as blank_file. Try to give more meaningful names to variables, be declarative. blank_file says hardly anything useful about the variable.
grps/usrs: Just for saving one or two characters now variables are harder to read.
Put spaces after commas.
Use (functional) list-comprehensions expressions instead of (imperative) for-loop statements whenever possible.
Use always "\n" for line endings (read and write), Python takes care of portability in all platforms.


I'd write:

import win32net

def write_group_members(server, input_groups, output_groups):
    with open(input_groups) as input_groups_fd:
        groups = [line.rstrip() for line in input_groups_fd]

    with open(output_groups, "w") as output_groups_fd:
        for group in groups:
            users = win32net.NetGroupGetUsers(server, group, 0)[0]
            for user in users:
                contents = "{0},{1}\n".format(group, user["name"])
                output_groups_fd.write(contents)

write_group_members("someserver.org", "groups.txt", "groups_members_output.txt")