Issue #24911: All socket objects are context managers; update examples

Doc/library/socket.rst

@@ -445,9 +445,6 @@ The following functions all create :ref:`socket objects <socket-objects>`.
    .. versionchanged:: 3.2
       *source_address* was added.
 
-   .. versionchanged:: 3.2
-      support for the :keyword:`with` statement was added.
-
 
 .. function:: fromfd(fd, family, type, proto=0)
 
@@ -831,6 +828,10 @@ Socket objects have the following methods.  Except for
 :meth:`~socket.makefile`, these correspond to Unix system calls applicable
 to sockets.
 
+.. versionchanged:: 3.2
+   Support for the :term:`context manager` protocol was added.  Exiting the
+   context manager is equivalent to calling :meth:`~socket.close`.
+
 
 .. method:: socket.accept()
 
@@ -1457,16 +1458,16 @@ The first two examples support IPv4 only. ::
 
    HOST = ''                 # Symbolic name meaning all available interfaces
    PORT = 50007              # Arbitrary non-privileged port
-   s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-   s.bind((HOST, PORT))
-   s.listen(1)
-   conn, addr = s.accept()
-   print('Connected by', addr)
-   while True:
-       data = conn.recv(1024)
-       if not data: break
-       conn.sendall(data)
-   conn.close()
+   with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+       s.bind((HOST, PORT))
+       s.listen(1)
+       conn, addr = s.accept()
+       with conn:
+           print('Connected by', addr)
+           while True:
+               data = conn.recv(1024)
+               if not data: break
+               conn.sendall(data)
 
 ::
 
@@ -1475,11 +1476,10 @@ The first two examples support IPv4 only. ::
 
    HOST = 'daring.cwi.nl'    # The remote host
    PORT = 50007              # The same port as used by the server
-   s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-   s.connect((HOST, PORT))
-   s.sendall(b'Hello, world')
-   data = s.recv(1024)
-   s.close()
+   with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+       s.connect((HOST, PORT))
+       s.sendall(b'Hello, world')
+       data = s.recv(1024)
    print('Received', repr(data))
 
 The next two examples are identical to the above two, but support both IPv4 and
@@ -1516,12 +1516,12 @@ sends traffic to the first one connected successfully. ::
        print('could not open socket')
        sys.exit(1)
    conn, addr = s.accept()
-   print('Connected by', addr)
-   while True:
-       data = conn.recv(1024)
-       if not data: break
-       conn.send(data)
-   conn.close()
+   with conn:
+       print('Connected by', addr)
+       while True:
+           data = conn.recv(1024)
+           if not data: break
+           conn.send(data)
 
 ::
 
@@ -1549,9 +1549,9 @@ sends traffic to the first one connected successfully. ::
    if s is None:
        print('could not open socket')
        sys.exit(1)
-   s.sendall(b'Hello, world')
-   data = s.recv(1024)
-   s.close()
+   with s:
+       s.sendall(b'Hello, world')
+       data = s.recv(1024)
    print('Received', repr(data))
 
 

Doc/library/socketserver.rst

@@ -465,17 +465,13 @@ This is the client side::
    data = " ".join(sys.argv[1:])
 
    # Create a socket (SOCK_STREAM means a TCP socket)
-   sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-
-   try:
+   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")
-   finally:
-       sock.close()
 
    print("Sent:     {}".format(data))
    print("Received: {}".format(received))
@@ -574,14 +570,11 @@ An example for the :class:`ThreadingMixIn` class::
        pass
 
    def client(ip, port, message):
-       sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-       sock.connect((ip, port))
-       try:
+       with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
+           sock.connect((ip, port))
            sock.sendall(bytes(message, 'ascii'))
            response = str(sock.recv(1024), 'ascii')
            print("Received: {}".format(response))
-       finally:
-           sock.close()
 
    if __name__ == "__main__":
        # Port 0 means to select an arbitrary unused port