How to load data from a JSON generated via mod-python

I'm having some trouble while loading JSON data from a cgi written开发者_JAVA技巧 in python. The python script sounds like this:

def get_data(req):
    #create a dictionary to be written as json
    req.write(str(dictionary)

I've used the same script with ext js so it's working, the problem is in the javascript. I'm creating the chart but I don't know how to read data from a remote python script, I didn't find any example or docs about this. How is this done?