question about for cycle

[fdu.xiaojf at gmail.com]

Hi all,

I have the following code:

for i in generator_a:  # the first "for" cycle
     for j in generator_b:
         if something_happen:
             # do something here ..., I want the outer cycle to break
             break

What should I do if I want the outer "for" cycle to continue or break ? If I 
put a "continue" or "break" in the inner cycle, it has no effect on the outer 
cycle.

And I have another question. Which is the most efficient way to check if there 
are duplicate items in a list ? The items in the list may cannot be hashed, so 
set() may not work on the list.

Regards,