Class Block

python/paddle/base/framework.py:4339–5116

In Fluid, a Program is consistence of multi-Block, and Block stores VarDesc and OpDesc. In a specific Block, a VarDesc have a unique name. One block could have some child blocks, and child block's name scopes should inherit the parent's so that OpDesc in child block can reference

class Block:
    """
    In Fluid, a Program is consistence of multi-Block, and Block stores
    VarDesc and OpDesc. In a specific Block, a VarDesc have a unique name.
    One block could have some child blocks, and child block's name scopes
    should inherit the parent's so that OpDesc in child block can reference
    a VarDesc that is stored in the parent block.
    Please reference the framework.proto for details.

    Args:
        program(Program): The Program that the Block belongs to.
        idx(int): The block's id in the Program.

    Notes:
        The constructor of Block should not be invoked directly. Please
        use `Program._create_block()` to create a block.

    Examples:
        .. code-block:: pycon

            >>> import paddle

            >>> paddle.enable_static()
            >>> cur_program = paddle.static.Program()
            >>> cur_block = cur_program.current_block()
            >>> var = cur_block.create_var(
            ...     name="X",
            ...     shape=[-1, 23, 48],
            ...     dtype="float32",
            ... )
            >>> cur_block.append_op(
            ...     type="abs",
            ...     inputs={"X": [var]},
            ...     outputs={"Out": [var]},
            ... )
    """

    def __init__(self, program, idx):
        self.desc = program.desc.block(idx)
        self.vars = collections.OrderedDict()  # var_name --> var
        self.ops = []  # operator list
        self.program = program

    def __str__(self):
        return self._to_readable_code()

    def _to_readable_code(self, skip_op_callstack=True):
        """
        Get readable debug string of Block.

        .. note::
            If you want to get the debug string in protobuf format,
            please use :code:`to_string` method.

        Args:
            skip_op_callstack(bool): whether to skip parsing Operator's attribute
                op_callstack, default value is True