Why does this Python script not print all keys in dict?

Why does this Python script not print all keys in dict?

def send_reminder(team_name,team_members):
for keys in team_members.keys():
print team_members
print keys
def main()
some calculations are done and a function is called ..
send_reminder(team[0],teams[team[0]])
Output is:
{'Primary': {'id': u'PVKYTY9'}, 'Secondary': {'id': u'PKC88YL'}}
Primary
Why does it does not print "Secondary" as key?