python实现dict版图遍历示例

#_*_coding:utf_8_
import sys
import os

class graph():
    def __init__(self, v, e):
        self.v = v
        self.e = e
        self.visited = []
        self.dict = {}
        self.fd = open("input.txt")

    def initgraph(self):
        self.visited = [0 for i in range(self.v+1)]
        for i in range(self.e):
            f, t = map(int, self.fd.readline().split())
            #f, t = map(int, sys.stdin.readline().split())
            if self.dict.has_key(f)==false:
                l = []
                l.append(t)
                self.dict[f] = l
            else:
                l = self.dict[f]
                l.append(t)
                self.dict[f] = l

   
    def dfsgraph(self, src):
        self.visited[src] = 1
        print src ,
        if self.dict.get(src): #self.dict[src]会出现异常
            for u in self.dict[src]:
                if self.visited[u]==0:
                    self.dfsgraph(u)

graph = graph(6, 10)
graph.initgraph()
graph.dfsgraph(1)

nput.txt

1 2
1 3
1 4
3 2
2 6
4 3
3 5
4 5
6 5
3 6

output:

1 2 6 5 3 4