old_contents: import re
  
  
  def matchdefault(pattern, string, default=''):
      """
      Search for pattern in string and return default string if no match.
      """
      regex = re.compile(pattern)
      match = regex.search(string)
      if match is not None:
          return match.group()
      else:
          return default
  
  def to_camel_case(snake_str):
      """
      Convert snake_case string to camelCase.
      """
      if re.search('_', snake_str):
          components = snake_str.split('_')
          return components[0] + ''.join(x.title() for x in components[1:])
      else:
          return snake_str
  
  def to_snake_case(camel_str):
      """
      Convert camelCase to snake_case.
      found function here:
      http://stackoverflow.com/questions/1175208/elegant-python-function-to-convert-camelcase-to-snake-case
      """
      s1 = re.sub('(.)([A-Z][a-z]+)', r'\1_\2', camel_str)
      return re.sub('([a-z0-9])([A-Z])', r'\1_\2', s1).lower()
  
new_contents: import re
  
  
  def matchdefault(pattern, string, default=''):
      """
      Search for pattern in string and return default string if no match
  
      :type pattern: str
      :param pattern: non-compiled regular expression to search for in
          input string
  
      :type string: str
      :param string: any string
  
      :type default: str
      :param default: string to return if no match found
  
      :rtype: str
      :return: substring matched to regular expression or default string,
          if no match found
      """
      regex = re.compile(pattern)
      match = regex.search(string)
      if match is not None:
          return match.group()
      else:
          return default
  
  
  def to_camel_case(snake_str):
      """
      Convert snake_case string to camelCase
  
      :type snake_str: str
      :param snake_str: a string in snake_case format
  
      :rtype: str
      :return: input string converted to camelCase format
      """
      if re.search('_', snake_str):
          components = snake_str.split('_')
          return components[0] + ''.join(x.title() for x in components[1:])
      else:
          return snake_str
  
  
  def to_snake_case(camel_str):
      """
      Convert camelCase to snake_case.
      found function here:
      http://stackoverflow.com/questions/1175208/elegant-python-function-to-convert-camelcase-to-snake-case
  
      :type camel_str: str
      :param camel_str: a string in camelCase format
  
      :rtype: str
      :return: input string converted to snake_case format
      """
      s1 = re.sub('(.)([A-Z][a-z]+)', r'\1_\2', camel_str)
      return re.sub('([a-z0-9])([A-Z])', r'\1_\2', s1).lower()
  
subject: add to sphinx docstrings in strings module