old_contents: import re
  from .filter import Filter
  
  
  class Regex(Filter):
  
      """ Matches filenames with the given regular expression
  
          Inputs:
              expr [str]  The regular expression to be matched
  
          Outputs:
              None
      """
  
      def __init__(self, expr):
          self.expr = re.compile(expr)
  
      def matches(self, path):
          return self.expr.match(path.name)
  
      def parse(self, path):
          return self.expr.match(path.name).groupdict()
  
new_contents: import re
  from .filter import Filter
  
  
  class Regex(Filter):
  
      """
      Matches filenames with the given regular expression
  
      :param str expr:
          The regular expression to be matched
      """
  
      def __init__(self, expr):
          self.expr = re.compile(expr)
  
      def matches(self, path):
          return self.expr.match(path.name)
  
      def parse(self, path):
          # TODO: regex.xyz namespace
          return self.expr.match(path.name).groupdict()
  
subject: update docs