TensorFlow 2 version View source on GitHub

Applies func to each entry in structure and returns a new structure.



Applies func(x[0], x[1], ...) where x[i] is an entry in structure[i]. All structures in structure must have the same arity, and the return value will contain results with the same structure layout.


  • func: A callable that accepts as many arguments as there are structures.
  • *structure: scalar, or tuple or list of constructed scalars and/or other tuples/lists, or scalars. Note: numpy arrays are considered as scalars.
  • **kwargs: Valid keyword args are:

    • check_types: If set to True (default) the types of iterables within the structures have to be same (e.g. map_structure(func, [1], (1,)) raises a TypeError exception). To allow this set this argument to False. Note that namedtuples with identical name and fields are always considered to have the same shallow structure.
    • expand_composites: If set to True, then composite tensors such as tf.SparseTensor and tf.RaggedTensor are expanded into their component tensors. If False (the default), then composite tensors are not expanded.


A new structure with the same arity as structure, whose values correspond to func(x[0], x[1], ...) where x[i] is a value in the corresponding location in structure[i]. If there are different sequence types and check_types is False the sequence types of the first structure will be used.


  • TypeError: If func is not callable or if the structures do not match each other by depth tree.
  • ValueError: If no structure is provided or if the structures do not match each other by type.
  • ValueError: If wrong keyword arguments are provided.