parameters: (output_dir)
return_statement: return key_file
docstring: Creates a keys.json file mapping Closure keys to Blockly keys.
  
      Args:
          output_dir: Relative directory for output files.
  
      Raises:
          IOError: An error occurred while creating the file.
docstring_summary: Creates a keys.json file mapping Closure keys to Blockly keys.
docstring_tokens: Creates a keys . json file mapping Closure keys to Blockly keys .
function: def _create_key_file(output_dir):
      """Creates a keys.json file mapping Closure keys to Blockly keys.
  
      Args:
          output_dir: Relative directory for output files.
  
      Raises:
          IOError: An error occurred while creating the file.
      """
      key_file_name = os.path.join(os.curdir, output_dir, 'keys.json')
      key_file = open(key_file_name, 'w')
      key_file.write('{\n')
      print 'Created file: ' + key_file_name
      return key_file
function_tokens: def _create_key_file ( output_dir ) : key_file_name = os . path . join ( os . curdir , output_dir , 'keys.json' ) key_file = open ( key_file_name , 'w' ) key_file . write ( '{\n' ) print 'Created file: ' + key_file_name return key_file