Calling Cloud Stack With Parameters

i am trying to make an api call using the below code and it works fine

import urllib2
import urllib
import hashlib
import hmac
import base64


baseurl='http://www.xxxx.com:8080/client/api?'
request={}
request['command']='listUsers'
request['response']='xml'
request['apikey']='xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'
secretkey='xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'
request_str='&'.join(['='.join([k,urllib.quote_plus(request[k])]) for k in request.keys()])
sig_str='&'.join(['='.join([k.lower(),urllib.quote_plus(request[k].lower().replace('+','%20'))])for k in sorted(request.iterkeys())])
sig=hmac.new(secretkey,sig_str,hashlib.sha1)
sig=hmac.new(secretkey,sig_str,hashlib.sha1).digest()
sig=base64.encodestring(hmac.new(secretkey,sig_str,hashlib.sha1).digest())
sig=base64.encodestring(hmac.new(secretkey,sig_str,hashlib.sha1).digest()).strip()
sig=urllib.quote_plus(base64.encodestring(hmac.new(secretkey,sig_str,hashlib.sha1).digest()).strip())
req=baseurl+request_str+'&signature='+sig
res=urllib2.urlopen(req)
result = res.read()
print result

what i want to know how can i send additional parameter with the Api call?? and how to send parameters when iam sending data to cloud stack instead of getting from the cloud stack e.g createuser

Add additional parameters to the the request dictionary.

E.g. listUsers allows details of a specific username to be listed (listUsers API Reference). To do so, you'd update request creation as follows:

request={}
request['command']='listUsers'
request['username']='admin'
request['response']='xml'
request['apikey']='xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'

Also the Rules for Signing say to "Lower case the entire Command String and sort it alphabetically via the field for each field-value pair" This section of the docs also covers adding an expiry to the URL.

Finally, you need to ensure the HTTP GET is not cached by network infrastructure by making each HTTP GET unique. The CloudStack API uses a cache buster. Alternatively, you can add an expiry to each query, or use an HTTP POST.