Understanding lists and dicts in Python3

client.py

string = "wELCOME tO cOMMODOREsERVER" # PETSCII has case reversed compared to ASCII
print("PETSCII: ", (string))
print("  ASCII: ", string.swapcase()) # "translate" PETSCII to ASCII
print("") # blank line

# '/roominfo' csip command displays verbose info about room
# '/rooms' csip command lists "'room_name' ['user_count']"

room_names = {'lOBBY', 'C64', 'C128', 'vIC-20', 'aMIGA', 'TED', 'PET', 'SANDBOX'}

user_count = (0, 5, 0, 0, 0, 0, 0, 0)

# user_names dict is mutable
# 1: always present
# 1234: the bot
user_names = {1: 'rOOM', 
	      1234: 'aRDIE',
	      12345: 'pINACOLADA',
	      54321: 'gOOG',
	      65535: 'aGENTfRIDAY'}

# TODO: creating a player ignore list might be cool

# TODO: usability feature: users should not have to know or type user ids to
# interact with a user. make a cursor-driven menu list of users somehow
# (at the very least, a numbered list to start with), e.g.:
# 1. Pinacolada
# 2. Goog
# 3. AgentFriday
# Which user? 2
# Private messaging Goog...

# rooms have a room/channel id also, i believe
# There are list.append and list.delete methods,
# so if a user enters or leaves a room, can .append or .delete the user id,
# which would map to a user name in some other function...

users_in_room = (1, 1234, 12345, 54321, 65535)

# def user_remove_from_room(id_to_remove):
# 	'''
#	Remove user from list of users in room
#	user could have disconnected or changed rooms
#	'''
#
#	try [...] # if user exists
#	except [...] # if user does not exist
#	print("[%s has left the room]", user_names(id_to_remove))
# 	users_in_room.delete(id_to_remove)

print("Users\tRoom name")
for u, r in zip(user_count, room_names):
	print(u, "\t", r.swapcase())

print("")

print("List users in room:")
print("ID\tUser name")
for u in users_in_room:
	print(u, "\t", user_names[u].swapcase() )

# id	user name
# 1 	Room
# 54321 Pinacolada
# 12345 Goog
# 65535	AgentFriday