generate all combinations of a list (with variable output length)

[thomas]

hi,

i'm looking for a way to generate all possible combinations of all items 
in a list. list = ["A","D","$","5","R"]

but i also want it to use one item several times or not at all and in no 
particular order. the length of the string is 1-10. so a possible output 
would be:

DD$
A5RD$D555
A
5RR$$A
DRRR55$5$A
...


i find it particualy difficult to tell python to use one item several 
times or not at all, and the variable length thing. i don't want to 
reinvent the wheel so someone probably has already a soultion for that 
:) and if not someone can probably push me in some direction.

thx,
thomas