import types

import urllib


def urlencode2(d):
    a = []
    for k in d:
        v = d[k]
        if type(v) == types.ListType:
            for x in v:
                a.append(urllib.urlencode({k: x}))
        else:
            a.append(urllib.urlencode({k: v}))
    return "&".join(a)

print urlencode2({"a": ["b", "c"]})
# Output: a=b&a=c

print urllib.urlencode({"a": ["b", "c"]})
# Output: wrong