python Beautiful Soup regexp 2

gistfile1.py

 # Methods for supporting CSS selectors.

    tag_name_re = re.compile('^[a-z0-9]+$')

    # /^(\w+)\[(\w+)([=~\|\^\$\*]?)=?"?([^\]"]*)"?\]$/
    #   \---/  \---/\-------------/    \-------/
    #     |      |         |               |
    #     |      |         |           The value
    #     |      |    ~,|,^,$,* or =
    #     |   Attribute
    #    Tag
    attribselect_re = re.compile(
        r'^(?P<tag>\w+)?\[(?P<attribute>\w+)(?P<operator>[=~\|\^\$\*]?)' +
        r'=?"?(?P<value>[^\]"]*)"?\]$'

...

    locatestarttagend = re.compile(r"""
  <[a-zA-Z][-.a-zA-Z0-9:_]*          # tag name
  (?:\s+                             # whitespace before attribute name
    (?:[a-zA-Z_][-.:a-zA-Z0-9_]*     # attribute name
      (?:\s*=\s*                     # value indicator
        (?:'[^']*'                   # LITA-enclosed value
          |\"[^\"]*\"                # LIT-enclosed value
          |[^'\">\s]+                # bare value
         )
       )?
     )
   )*
  \s*                                # trailing whitespace
""", re.VERBOSE)