Easy Wifi Connection via Python

Python Wifi Connectivity Script For Linux

#!/bin/python
#
# Connects to a Wifi network
#

import os

def commandExists(command):
    def canExecute(file):
        return os.path.isfile(file) and os.access(file, os.X_OK)
    for path in os.environ["PATH"].split(os.pathsep):
        file = os.path.join(path, command)
        if canExecute(file):
            return True
    return False

print "Checking for root access..."
user = os.popen("whoami").read()
if 'root' not in user:
    print 'You need to be the root user to run this program and you are running as '+user+'  Try sudo python <ScriptName>.py'
    print 'Exiting...'
    quit()
else:
    print 'Good job, you\'re root.'

print "Trying to activate the default wlan0 network..."
if not commandExists("ifconfig"):
    print "You will need the command 'ifconfig' to continue."
    quit()
status = os.popen("ifconfig wlan0 up").read()
if 'No such device' in status:
    print "It seems your wireless device is not named wlan0, so you're going to need to enter it manually."
    winame = raw_input('Wireless Device Name: ')
else:
    winame = "wlan0"
print "Wireless device enabled!"
print "Checking for available wireless networks..."
stream = os.popen("iwlist " + winame + " scan")
print "Available Networks:"
networksfound = 0
for line in stream:
    if "ESSID" in line:
        networksfound += 1
        print " " + line.split('ESSID:"', 1)[1].split('"', 1)[0]
if networksfound == 0:
    print "Looks like we didn't find any networks in your area. Exiting..."
    quit()
network = raw_input("Please enter your network: ")
tpass = raw_input("Please enter the network's pass (Blank for none): ")
if tpass == '':
    os.popen("iwconfig " + winame + " essid " + network)
else:
    connectstatus = os.popen("iwconfig " + winame + " essid " + network + " key s:" + tpass)
print "Connecting..."
if not commandExists("dhclient"):
    print "Looks like there isn't a dhclient program on this computer. Trying dhcpd (Used with Arch)"
    con2 = os.popen("dhcpcd " + winame).read()
    print con2
    if not commandExists("dhcpcd"):
        print "Well, I'm out of options. Try installing dhcpd or dhclient."
        quit()    
else:
    os.popen("dhclient " + winame)
ontest = os.popen("ping -c 1 google.com").read()
if ontest == '':
    print "Connection failed. (Bad pass?)"
    quit()
print "Connected successfully!"
quit()

Not working properly here in ubuntu 18.04.
"Error for wireless request "Set Encode" (8B2A) :
SET failed on device wlan0 ; Invalid argument."
Can you tell how it can be resolved?