def unseq(seq):
    return seq[0] if len(seq) == 1 else seq



#def flatten(obj):
#    try:
#        iter(obj)
#    except TypeError:
#        return [obj]
#    else:
#        res = []
#        for i in obj:
#            res.extend(flatten(i))
#        return res



def flatten(obj):
    return list(iflatten(obj))

def iflatten(obj):
    try:
        iterator = iter(obj)
    except TypeError:
        yield obj
    else:
        for item in iterator:
            yield from iflatten(item)