`scipy.cluster.hierarchy:ClusterNode.pre_order`

Signature

def pre_order ( self , func = <function ClusterNode.<lambda> at 0x0000> )

Perform 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.