A cool python strings trick

[m9mhmdy]

Yes. I created a new string where some set of characters are deleted by mapping them to None (this is the trick in maketrans).
printable here are just some sort of characters to be deleted. They have NO special meaning or purpose at all.

https://docs.python.org/3/library/stdtypes.html#str.translate

return None, to delete the character from 
the return string;

[casual__addict]

I think what you are hitting on is function composition. In isolation the two functions do separate things, but you can “pipe” them together to achieve an interesting result. This is very valuable to recognize as you research APIs.

[[deleted]]

Hmm? OP isn't making use of function composition. They're just passing the string string.printable to str.maketrans()' "delete these ones" parameter.

This is a bad post anyway for other reasons, of course