Tree Walking¶
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class
anytree.walker.
Walker
[source]¶ Bases:
object
Walk from one node to another.
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walk
(start, end)[source]¶ Walk from start node to end node.
- Returns:
- (upwards, downwards): upwards is a list of edges to parent nodes to go upward to. downwards is a list of edges to child nodes to go downward to.
- Raises:
- WalkError: on no common root node.
>>> from anytree import Node, RenderTree, AsciiStyle >>> f = Node("f") >>> b = Node("b", parent=f) >>> a = Node("a", parent=b) >>> d = Node("d", parent=b) >>> c = Node("c", parent=d) >>> e = Node("e", parent=d) >>> g = Node("g", parent=f) >>> i = Node("i", parent=g) >>> h = Node("h", parent=i) >>> print(RenderTree(f, style=AsciiStyle())) Node('/f') |-- Node('/f/b') | |-- Node('/f/b/a') | +-- Node('/f/b/d') | |-- Node('/f/b/d/c') | +-- Node('/f/b/d/e') +-- Node('/f/g') +-- Node('/f/g/i') +-- Node('/f/g/i/h')
Create a walker:
>>> w = Walker()
This class is made for walking:
>>> w.walk(f, f) ([], []) >>> w.walk(f, b) ([], [Node('/f/b')]) >>> w.walk(b, f) ([Node('/f')], []) >>> w.walk(a, f) ([Node('/f/b'), Node('/f')], []) >>> w.walk(b, f) ([Node('/f')], []) >>> w.walk(h, e) ([Node('/f/g/i'), Node('/f/g'), Node('/f')], [Node('/f/b'), Node('/f/b/d'), Node('/f/b/d/e')])
For a proper walking the nodes need to be part of the same tree:
>>> w.walk(Node("a"), Node("b")) Traceback (most recent call last): ... anytree.walker.WalkError: Node('/a') and Node('/b') are not part of the same tree.
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