if /else statement not executing correctly

[bluethundr]

I am trying to get a list of groups in an aws account. Then allow a user to add the groups to a user name, until the user enters quit:

group_list = client.list_groups()
all_groups = []
for group in group_list['Groups']:
    group_name = group['GroupName']

all_groups.append(group_name)
    for group_name in all_groups:
        print(group_name)

add_group_name = ''
while add_group_name != 'quit':
    add_group_name = input("Enter the group name to add to user %s: " % user_name)
    if add_group_name == 'quit':
    break
else:
    print("Add user to group.")
    client.add_user_to_group(GroupName=add_group_name,UserName=user_name)

What happens is that the line:

client.add_user_to_group(GroupName=add_group_name,UserName=user_name)

never gets executed. How can I change this so thtat this line gets executed? Also is there a better way of doing this?