Python 3.6 sre_parse module

Why

The initial motivation to "create" sre_parse36 is to provide a colorizer for regular expressions that produce the same expression as initially provided.

The handling of non-capturing groups changed from Python 3.7, we can't back reproduce the original regular expression from a SubPattern instance anymore. This regression is tracked at https://bugs.python.org/issue45674, hopefully it will be fixed in a future Python 3.9 bugfix release.

In Python 3.6:

>>> import sre_parse
>>> sre_parse.parse("(?:foo (?:bar) | (?:baz))").dump()
SUBPATTERN None 0 0
  BRANCH
    LITERAL 102
    LITERAL 111
    LITERAL 111
    LITERAL 32
    SUBPATTERN None 0 0
      LITERAL 98
      LITERAL 97
      LITERAL 114
    LITERAL 32
  OR
    LITERAL 32
    SUBPATTERN None 0 0
      LITERAL 98
      LITERAL 97
      LITERAL 122

In Python 3.7 and beyond:

>>> import sre_parse
>>> sre_parse.parse("(?:foo (?:bar) | (?:baz))").dump()
BRANCH
  LITERAL 102
  LITERAL 111
  LITERAL 111
  LITERAL 32
  LITERAL 98
  LITERAL 97
  LITERAL 114
  LITERAL 32
OR
  LITERAL 32
  LITERAL 98
  LITERAL 97
  LITERAL 122

Install

pip install sre_parse36

Usage

Replace sre_parse by sre_parse36.