Note that any dictionary key whose value is ``None`` will not be added to the
URL's query string.
+In order to pass a list of items as a value you must mark the key as
+referring to a list like string by appending ``[]`` to the key::
+
+ >>> payload = {'key1': 'value1', 'key2[]': ['value2', 'value3']}
+ >>> r = requests.get("http://httpbin.org/get", params=payload)
+ >>> print(r.url)
+ http://httpbin.org/get?key1=value1&key2%5B%5D=value2&key2%5B%5D=value3
Response Content
----------------