Function dfs

Lib/asyncio/tools.py:124–134

(v)

    path, cycles = [], []

    def dfs(v):
        color[v] = GREY
        path.append(v)
        for w in graph.get(v, ()):
            if color[w] == WHITE:
                dfs(w)
            elif color[w] == GREY:            # back-edge → cycle!
                i = path.index(w)
                cycles.append(path[i:] + [w])  # make a copy
        color[v] = BLACK
        path.pop()

    for v in list(graph):
        if color[v] == WHITE: