How to check if a specific port is listening using Python script?
Question: I want to check if api and app are running before running tests on them. I
know I can get a list of open ports in CLI using

`sudo lsof -iTCP -sTCP:LISTEN -n -P`

But I want to write a python script to do so. Any ideas on what library should
I use or how should I do that?


Answer: I found a port checker using socket
[here](http://code.activestate.com/recipes/577769-tcp-port-checker/) and it
works.

    
    
    #!/usr/bin/env python
    # -*- coding: utf-8 -*-
    
    import socket
    import re
    import sys
    def check_server(address, port):
        # Create a TCP socket
        s = socket.socket()
        print "Attempting to connect to %s on port %s" % (address, port)
        try:
            s.connect((address, port))
            print "Connected to %s on port %s" % (address, port)
            return True
        except socket.error, e:
            print "Connection to %s on port %s failed: %s" % (address, port, e)
            return False
    
    if __name__ == '__main__':
        from optparse import OptionParser
        parser = OptionParser()
    
        parser.add_option("-a", "--address", dest="address", default='localhost', help="ADDRESS for server", metavar="ADDRESS")
    
        parser.add_option("-p", "--port", dest="port", type="int", default=80, help="PORT for server", metavar="PORT")
    
        (options, args) = parser.parse_args()
        print 'options: %s, args: %s' % (options, args)
        check = check_server(options.address, options.port)
        print 'check_server returned %s' % check
    
        sys.exit(not check)
    

