Hello I am trying to understand a program which use a method named scanner on a re compiled object. This program is named "Simple compiler" here: https://www.pythonsheets.com/notes/python-generator.html But unfortunately it is not documented nor here: https://docs.python.org/3.7/library/re.html#regular-expression-objects nor with help import re lex = re.compile("foo") help(lex.scanner) Help on built-in function scanner: scanner(string, pos=0, endpos=2147483647) method of _sre.SRE_Pattern instance Does anybody know where to find a doc ?