I use Python 3.4.2 on linux here's my code.
myurl = 'http://localhost/test.php'
response = urllib.urlopen(myurl) 
while response.text != 'exit':
    response = urllib.urlopen(myurl)  
And i got this error
  Traceback (most recent call last) :
     File "/var/www/html/led.py", line 19, in <module>
        response = urllib.urlopen(myurl)
  AttributeError: 'module' object has no attribute 'urlopen'