Documentation of ast.walk misleadingly characterizes its behavior as recursive when it's really iterative

Documentation

Although the documentation claims that ast.walk generates nodes "in no specified order" and even describes its behavior as "Recursively yield all descendant nodes...", a look at the source code reveals that it really performs a breadth-first traversal by iteratively yielding child nodes in a queue:

def walk(node):
    """
    Recursively yield all descendant nodes in the tree starting at *node*
    (including *node* itself), in no specified order.  This is useful if you
    only want to modify nodes in place and don't care about the context.
    """
    from collections import deque
    todo = deque([node])
    while todo:
        node = todo.popleft()
        todo.extend(iter_child_nodes(node))
        yield node

I thought that maybe this function used to be recursive but found that it has not been modified since its first appearance in CPython 2.6.3.

I think we should at the minimum remove the wording "Recursively" from the description, and optionally:

1. Clarify the actual ordering by changing "in no specified order" to "in breadth-first order".
2. Add a keyword argument such as depth_first that defaults to False such that when it is true, switches to a depth-first traversal that behaves like:

def dfs_walk(node):
    yield node
    for child in ast.iter_child_nodes(node):
        yield from dfs_walk(child)

Inizia dalla documentazione di ast.walk collegata nell’issue e confrontane la formulazione con l’implementazione in Lib/ast.py. Decidi se apportare la correzione minima alla formulazione o documentare anche l’ordine di attraversamento in ampiezza; la documentazione deve descrivere accuratamente il comportamento esistente senza aggiungere una modifica dell’API non richiesta.