parse_formdata.py

import cgi


def parse_form_data(formdata):
    fp = cgi.StringIO(formdata)
    env = cgi.os.environ
    env['REQUEST_METHOD'] = 'POST'
    data = cgi.FieldStorage(fp, environ=env)
    return data

Here is an example

In [2]: fdata = 'user=toto&pass=toto'

In [3]: data = parse_form_data(fdata)

In [4]: data['user'].value
Out[4]: 'toto'

In [5]: data['pass'].value
Out[5]: 'toto'

In [6]: