Python for循环查询

Question

I am checking a piece of Python code I found online ( http://www.exploit-db.com/exploits/18305/ ), and I'm stuck trying to understand a seemingly simple for loop.

To be honest I don't know Python, but I have experience in other programming languages.

def _generatePayload(self, collisionchars, payloadlength):
    result = ""

    for item in collisionchars:
        result = result.replace(str(item), collisionchars[item])

    return result;

I have modified the code slightly to remove the parts that are irrelevant to the question, but I have retained the same method definition as found in the original source. As I understand this, it is replacing a string (within a char array / string) by another string which has the same value??

Thanks a bunch guys!

Answer 1

collisionchars seems to be a dict (note the indexer).

What the code does is loop through all keys of collisionchars , and replace each occurence of that key in result with the value of that key.

So, if collisionchars = {'a': 'X', 'o': '_'} and result = 'FooBar' , the code would alter result to F__BXr (replacing each a with X and each o with _ ).