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visitor

ModelTransformer

Bases: NodeTransformer, VisitorFinder

NodeTransformer that supports matching nodes based on their base classes.

See :class:ModelVisitor for explanation how this is different compared to the standard ast.NodeTransformer <https://docs.python.org/library/ast.html#ast.NodeTransformer>__.

Source code in src/robot/parsing/model/visitor.py 
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class ModelTransformer(NodeTransformer, VisitorFinder):
    """NodeTransformer that supports matching nodes based on their base classes.

    See :class:`ModelVisitor` for explanation how this is different compared
    to the standard `ast.NodeTransformer
    <https://docs.python.org/library/ast.html#ast.NodeTransformer>`__.
    """

    def visit(self, node: Node) -> 'None|Node|list[Node]':
        visitor_method = self._find_visitor(type(node))
        return visitor_method(self, node)

ModelVisitor

Bases: NodeVisitor, VisitorFinder

NodeVisitor that supports matching nodes based on their base classes.

The biggest difference compared to the standard ast.NodeVisitor <https://docs.python.org/library/ast.html#ast.NodeVisitor>__, is that this class allows creating visit_ClassName methods so that the ClassName is one of the base classes of the node. For example, the following visitor method matches all node classes that extend Statement::

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def visit_Statement(self, node):
    ...

Another difference is that visitor methods are cached for performance reasons. This means that dynamically adding visit_Something methods does not work.

Source code in src/robot/parsing/model/visitor.py 
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class ModelVisitor(NodeVisitor, VisitorFinder):
    """NodeVisitor that supports matching nodes based on their base classes.

    The biggest difference compared to the standard `ast.NodeVisitor
    <https://docs.python.org/library/ast.html#ast.NodeVisitor>`__,
    is that this class allows creating ``visit_ClassName`` methods so that
    the ``ClassName`` is one of the base classes of the node. For example,
    the following visitor method matches all node classes that extend
    ``Statement``::

        def visit_Statement(self, node):
            ...

    Another difference is that visitor methods are cached for performance
    reasons. This means that dynamically adding ``visit_Something`` methods
    does not work.
    """

    def visit(self, node: Node) -> None:
        visitor_method = self._find_visitor(type(node))
        visitor_method(self, node)