Help with searching a list

[Jeff Epler]

# Replace this with a more sophisticated test if you prefer
def flattenable(o): return type(o) == list

def flatten(x, b = None):
    if b is None: b = []
    for i in x:
        if flattenable(i):
            flatten(i, b)
        else:
            b.append(i)
    return b

def flatten_generator(x):
    for i in x:
        if flattenable(i):
            for j in flatten(i): yield j
        else:
            yield i

Jeff