Hello all , string.lstrip("source/old_prog","source/") return "ld_prog" instead of "old_prog"
You are misunderstanding what the second argument to lstrip does. It is interpreted as a list of characters; and lstrip will remove the maximal prefix of the string that consists of these characters. E.g.:
The first character in your string that is not one of the characters 's', 'o', 'u', 'r', 'c', 'e', or '/' is 'l', so it strips all characters up to that one.