You need to pass your parameters into urlencode()
as either a mapping (dict), or a sequence of 2-tuples, like:
>>> import urllib
>>> f = { 'eventName' : 'myEvent', 'eventDescription' : 'cool event'}
>>> urllib.urlencode(f)
'eventName=myEvent&eventDescription=cool+event'
Python 3 or above
Use:
>>> urllib.parse.urlencode(f)
eventName=myEvent&eventDescription=cool+event
Note that this does not do url encoding in the commonly used sense (look at the output). For that use urllib.parse.quote_plus
.