there's far too many IRC client implementations out in the world that do not tokenise data correctly and thus fall victim to things like colons either being where you don't expect them or not being where you expect them.
$ pip3 install irctokens
>>> import irctokens
>>> line = irctokens.tokenise(
... "@id=123 :jess!~jess@hostname PRIVMSG #chat :hello there!")
>>>
>>> line.tags
{'id': '123'}
>>> line.source
'jess!~jess@hostname'
>>> line.hostmask
Hostmask(nickname='jess', username='~jess', hostname='hostname')
>>> line.command
'PRIVMSG'
>>> line.params
['#chat', 'hello there!']
>>> irctokens.format("USER", ["user", "0", "*", "real name"])
'USER user 0 * :real name'
below is an example of a fully socket-wise safe IRC client connection that will connect and join a channel. both protocol sending and receiving are handled by irctokens.
import irctokens, socket
NICK = "nickname"
CHAN = "#channel"
d = irctokens.StatefulDecoder()
e = irctokens.StatefulEncoder()
s = socket.socket()
s.connect(("127.0.0.1", 6667))
def _send(line):
print(f"> {line.format()}")
e.push(line)
while e.pending():
e.pop(s.send(e.pending()))
_send(irctokens.format("USER", ["username", "0", "*", "real name"]))
_send(irctokens.format("NICK", [NICK]))
while True:
lines = d.push(s.recv(1024))
if lines == None:
print("! disconnected")
break
for line in lines:
print(f"< {line.format()}")
if line.command == "PING":
to_send = irctokens.format("PONG", [line.params[0]])
_send(to_send)
elif line.command == "001":
to_send = irctokens.format("JOIN", [CHAN])
_send(to_send)