parameters: (path_name)
return_statement: return ''.join(result)
docstring: Converts a field name from camelCase to snake_case.
docstring_summary: Converts a field name from camelCase to snake_case.
docstring_tokens: Converts a field name from camelCase to snake_case .
function: def _CamelCaseToSnakeCase(path_name):
    """Converts a field name from camelCase to snake_case."""
    result = []
    for c in path_name:
      if c == '_':
        raise ValueError('Fail to parse FieldMask: Path name '
                         '{0} must not contain "_"s.'.format(path_name))
      if c.isupper():
        result += '_'
        result += c.lower()
      else:
        result += c
    return ''.join(result)
function_tokens: def _CamelCaseToSnakeCase ( path_name ) : result = [ ] for c in path_name : if c == '_' : raise ValueError ( 'Fail to parse FieldMask: Path name ' '{0} must not contain "_"s.' . format ( path_name ) ) if c . isupper ( ) : result += '_' result += c . lower ( ) else : result += c return '' . join ( result )