code: def generate_private_key(key_type):
      
      if key_type == u'rsa':
          return rsa.generate_private_key(
              public_exponent=65537, key_size=2048, backend=default_backend())
      raise ValueError(key_type)
docs: Generate a random private key using sensible parameters.
  
      :param str key_type: The type of key to generate. One of: ``rsa``.