How to remove those "\x00\x00"

I think the more general solution is to use:

cleanstring = nullterminatedstring.split('\x00',1)[0]

Which will split the string using \x00 as the delimeter 1 time. The split(...) returns a 2 element list: everything before the null in addition to everything after the null (it removes the delimeter). Appending [0] only returns the portion of the string before the first null (\x00) character, which I believe is what you're looking for.

The convention in some languages, specifically C-like, is that a single null character marks the end of the string. For example, you should also expect to see strings that look like:

'Hello\x00dpiecesofsomeoldstring\x00\x00\x00'

The answer supplied here will handle that situation as well as the other examples.

Use rstrip

>>> text = 'Hello\x00\x00\x00\x00'
>>> text.rstrip('\x00')
'Hello'

It removes all \x00 characters at the end of the string.

>>> a = 'Hello\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00' 
>>> a.replace('\x00','')
'Hello'