Simple Socket Connection Test in Python 3

In the continuing vein of updating/refreshing my older python posts for Python  3,

I have outlined the changes necessary to test for open TCP ports using Python  3.

My original post showed you how to open a socket connection to a host:port to see if it was active and accepting connections. Luckily, this time around I didn’t have to change much of anything. Turns out the only missing links were my print statements. As I mentioned in my last post, Python3 has turned the print statement into a function.

I also added some slightly better error handling to the example. If a connection fails, you can now see the cause of the failure.

Things to remember:

  • You can use an ip or hostname for the host variable value.
  • You can test UDP sockets by changing socket.SOCK_STREAM to socket.SOCK_DGRAM.
    import socket
    #Simply change the host and port values
    host = ''
    port = 80
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        s.connect((host, port))
        print("Success connecting to ")
        print(host," on port: ",str(port))
    except socket.error as e:
        print("Cannot connect to ")
        print(host," on port: ",str(port))

As always, I appreciate any feedback or modifications that would make this example more useful or easy to understand.

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  1. Thanks for posting this and your other Python posts…there’s a tiny typo in this post – there is no need for the second : after the ‘except socket.error as e:’ statement

  2. Very short and easy solution. I tried successfully. But what if the client has to use a proxy to reach the remote host. That seems to be quite complicated. But this is my problem.
    Can you help me please?

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