string permutation

perm.py

def perm(string):
    if len(string) <= 1:
        return [string]
    return [i+j for idx,i in enumerate(string)
                for j in perm(string[0:idx] + string[idx+1:])]

if __name__ == "__main__":
    TCs = [
            ("a", ["a"]),
            ("ao", ["ao", "oa"])
            ]

    for TC in TCs:
        if perm(TC[0]) == TC[1]:
            print("SUCCEED TC: %s" % TC[0])
        else:
            print("FAILED TC: %s" % TC[0])