- ClusterNode.pre_order(func=<function <lambda> at 0x2b31fc7c22a8>)¶
Performs pre-order traversal without recursive function calls.
When a leaf node is first encountered, func is called with the leaf node as its argument, and its result is appended to the list.
For example, the statement:
ids = root.pre_order(lambda x: x.id)
returns a list of the node ids corresponding to the leaf nodes of the tree as they appear from left to right.
func : function
Applied to each leaf ClusterNode object in the pre-order traversal. Given the i’th leaf node in the pre-ordeR traversal n[i], the result of func(n[i]) is stored in L[i]. If not provided, the index of the original observation to which the node corresponds is used.
L : list
The pre-order traversal.