I have been trying to debug this error I've been getting for a while to no success. It is a basic socket program using python that takes in a lower case sentence from the client and the server returns it in uppercase form. The client file works perfectly fine, however I keep getting this error when trying to run "python server.py" in the console, returning this message:
[yanb@athena:45]> python server.py
Traceback (most recent call last):
  File "server.py", line 7, in <module>
    serverSocket.bind(('',serverPort))
  File "< string >", line 1, in bind
socket.error: [Errno 98] Address already in use
Here is my code:
client.py
    from socket import *
    serverName = '127.0.0.1'
    serverPort = 12000
    clientSocket = socket(AF_INET, SOCK_STREAM)
    clientSocket.connect((serverName,serverPort))
    sentence = raw_input('Input lowercase sentence:')
    clientSocket.send(sentence)
    modifiedSentence = clientSocket.recv(1024)
    print 'From Server:', modifiedSentence
    clientSocket.close()
server.py
    from socket import *
    serverPort = 12000
    serverSocket = socket(AF_INET,SOCK_STREAM)
    serverSocket.bind(('',serverPort))
    serverSocket.listen(1)
    print 'The server is ready to receive'
     while 1:
     connectionSocket, addr = serverSocket.accept()
     sentence = connectionSocket.recv(1024)
     capitalizedSentence = sentence.upper()
     connectionSocket.send(capitalizedSentence)
     connectionSocket.close()
 
    