All combinations of a list

[June Kim]

Below is my first version of doing it:

def comb(list):
    if len(list) ==0:
           return [[]]
    return [ [[list[0]],[]][i]+c for i in (0,1) \
           for c in comb(list[1:]) ]

That works fine, but why does another version using
lambda give a subscription error?

def comb(list):
    if len(list) ==0:
           return [[]]
    return  map(lambda x: [list[0]]+x , comb(list[1:]))  \
             + comb(list[1:])

Thanks in advance.

June

[This thread was first started from permutation lists
and now that the topic has moved somewhat far from
the originator's question, I open up this thread as a new one]