title: Python Socket : AttributeError: __exit__
body: <p>I try to run example from : <a href="https://docs.python.org/3/library/socketserver.html#socketserver-tcpserver-example" rel="noreferrer">https://docs.python.org/3/library/socketserver.html#socketserver-tcpserver-example</a>
  in my laptop but it didn't work.</p>
  
  <p>Server :</p>
  
  <pre><code>import socketserver
  
  class MyTCPHandler(socketserver.BaseRequestHandler):
      """
      The request handler class for our server.
  
      It is instantiated once per connection to the server, and must
      override the handle() method to implement communication to the
      client.
      """
  
      def handle(self):
          # self.request is the TCP socket connected to the client
          self.data = self.request.recv(1024).strip()
          print("{} wrote:".format(self.client_address[0]))
          print(self.data)
          # just send back the same data, but upper-cased
          self.request.sendall(self.data.upper())
  
  if __name__ == "__main__":
      HOST, PORT = "localhost", 9999
  
      # Create the server, binding to localhost on port 9999
      with socketserver.TCPServer((HOST, PORT), MyTCPHandler) as server:
          # Activate the server; this will keep running until you
          # interrupt the program with Ctrl-C
          server.serve_forever()
  </code></pre>
  
  <p>Client :</p>
  
  <pre><code>import socket
  import sys
  
  HOST, PORT = "localhost", 9999
  data = " ".join(sys.argv[1:])
  
  # Create a socket (SOCK_STREAM means a TCP socket)
  with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
      # Connect to server and send data
      sock.connect((HOST, PORT))
      sock.sendall(bytes(data + "\n", "utf-8"))
  
      # Receive data from the server and shut down
      received = str(sock.recv(1024), "utf-8")
  
  print("Sent:     {}".format(data))
  print("Received: {}".format(received))
  </code></pre>
  
  <p>This error is showing on both client and server site :</p>
  
  <pre><code>Traceback (most recent call last):
    File "C:\Users\Win7_Lab\Desktop\testcl.py", line 8, in &lt;module&gt;
      with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
  AttributeError: __exit__
  [Finished in 0.1s with exit code 1]
  [shell_cmd: python -u "C:\Users\Win7_Lab\Desktop\testcl.py"]
  [dir: C:\Users\Win7_Lab\Desktop]
  [path: C:\Python27\;C:\Python27\Scripts;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\]
  </code></pre>