import socket

SERVER$\_$HOST $=\text{'}127\mathrm{.}0\mathrm{.}0\mathrm{.}1\text{'}$

SERVER$\_$PORT $=5378$

FORBIDDEN$\_$SYMBOLS $="!$@#$$\%^$&$*"$

def read$\_$usernames$()$:

usernames $=$ set$()$

try:

with open$("$usernames$.$txt$","$r$")$ as file:

for line in file:

usernames.add$($line$.$strip$())$

except FileNotFoundError:

pass # Dosya bulunamazsa bo$$ bir k$$me d$$nd$$r

return usernames

def write$\_$username$($username$)$:

with open$("$usernames$.$txt$","$a$")$ as file:

file.write$($username $+"$

$")$

print$(\text{'}$Welcome to Chat Client. Enter your login:$\text{'})$

username $=$ input$()$

existing$\_$usernames $=$ read$\_$usernames$()$

forbidden $=$ False

for symbol in FORBIDDEN$\_$SYMBOLS:

if symbol in username:

forbidden $=$ True

break

if forbidden:

print$($f$"$Cannot log in as $\{$username$\}.$ That username contains disallowed characters."$)$

elif username in existing$\_$usernames:

print$($f$"$Cannot log in as $\{$username$\}.$ That username is already in use."$)$

else:

existing$\_$usernames.add$($username$)$

write$\_$username$($username$)$

try:

client$\_$socket $=$ socket.socket$($socket$.$AF$\_$INET, socket.SOCK$\_$STREAM$)$

host$\_$port $=($SERVER$\_$HOST, SERVER$\_$PORT$)$

client$\_$socket.connect$($host$\_$port$)$

print$($f$"$Successfully logged in as $\{$username$\}!")$

data $=$ client$\_$socket.recv$(4096)$

if not data:

print$("$Socket is closed."$)$

else:

print$($f$"$Read data from socket: $\{$data$.$decode$()\}")$

client$\_$socket.close$()$

except OSError as msg:

print$($msg$)$

I am getting errors which are shown in the below. Can you help me to fix them?

$[$ x $]$ chat$\_005.$ Expect client to not restart after a failed log in attempt Failed! The list of tags is RI$1$ RT$7$ RA$6$

Your client did not start or connected to a wrong server port

$[$ x $]$ chat$\_006.$ Log in with busy server, expect failure, and shut client down gracefully Failed! The list of tags is RI$1$ RT$7$ RI$6$

Error message is unexpected output at step logging into busy server!

Expected output:

Cannot log in$.$ The server is full!

Actual output $($the last printed line$)$:

Successfully logged in as aRsnlrRvAMMwv!

Total program output:

Welcome to Chat Client. Enter your login:

aRsnlrRvAMMwv

Successfully logged in as aRsnlrRvAMMwv!