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from .abstractiter import AbstractIter |
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class PreOrderIter(AbstractIter): |
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""" |
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Iterate over tree applying pre-order strategy starting at `node`. |
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Start at root and go-down until reaching a leaf node. |
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Step upwards then, and search for the next leafs. |
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>>> from anytree import Node, RenderTree, AsciiStyle, PreOrderIter |
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>>> f = Node("f") |
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>>> b = Node("b", parent=f) |
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>>> a = Node("a", parent=b) |
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>>> d = Node("d", parent=b) |
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>>> c = Node("c", parent=d) |
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>>> e = Node("e", parent=d) |
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>>> g = Node("g", parent=f) |
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>>> i = Node("i", parent=g) |
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>>> h = Node("h", parent=i) |
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>>> print(RenderTree(f, style=AsciiStyle()).by_attr()) |
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f |
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|-- b |
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| |-- a |
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| +-- d |
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| |-- c |
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| +-- e |
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+-- g |
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+-- i |
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+-- h |
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>>> [node.name for node in PreOrderIter(f)] |
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['f', 'b', 'a', 'd', 'c', 'e', 'g', 'i', 'h'] |
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>>> [node.name for node in PreOrderIter(f, maxlevel=3)] |
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['f', 'b', 'a', 'd', 'g', 'i'] |
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>>> [node.name for node in PreOrderIter(f, filter_=lambda n: n.name not in ('e', 'g'))] |
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['f', 'b', 'a', 'd', 'c', 'i', 'h'] |
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>>> [node.name for node in PreOrderIter(f, stop=lambda n: n.name == 'd')] |
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['f', 'b', 'a', 'g', 'i', 'h'] |
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""" |
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@staticmethod |
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def _iter(children, filter_, stop, maxlevel): |
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for child_ in children: |
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if stop(child_): |
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continue |
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if filter_(child_): |
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yield child_ |
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if not AbstractIter._abort_at_level(2, maxlevel): |
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descendantmaxlevel = maxlevel - 1 if maxlevel else None |
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for descendant_ in PreOrderIter._iter(child_.children, filter_, stop, descendantmaxlevel): |
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yield descendant_ |
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