Python 2 阅读行问题

Question

我正在尝试构建一些离散优化算法（构建 djisktra、flowd warshall 和 bellman ford），我在 python3 中构建了它，但实际上我在 python2 中需要它，问题来了...

这是我的代码：

import os.path

def dict_fromFile():
    fn = os.path.join(os.path.dirname(__file__), 'metroEdgeDist.txt')
    f = open(fn, 'r')
    i=0
    dict_voisins = {}
    nb_sommets = f.readline()
    list_temp = {}
    for line in f:
        nb_voisins = line
        for nb in range(0,int(nb_voisins)):
            tempSommet = f.readline()
            tempPoids = f.readline()
            list_temp.update({int(tempSommet.replace("\n","")):float(tempPoids.replace("\n",""))})
        dict_voisins[i]= list_temp
        list_temp = {}
        i+=1
    f.close()
    return dict_voisins

def mat_fromFile():
    fn = os.path.join(os.path.dirname(__file__), 'metroEdgeDist.txt')
    f = open(fn, 'r')
    i=0
    nb_sommets = int(f.readline())
    mat_voisins = [[ float('inf') for i in range(nb_sommets) ] for j in range(nb_sommets) ]
    for line in f:
        nb_voisins = line
        for nb in range(0,int(nb_voisins)):
            tempSommet = f.readline()
            tempPoids = f.readline()
            mat_voisins[i][int(tempSommet.replace("\n",""))] = float(tempPoids.replace("\n",""))
        mat_voisins[i][i]=0 
        i+=1
    f.close()
    return mat_voisins

所以问题是"Mixing iterations"...但实际上我不知道这样做有什么不同...

问题是我需要 for 循环中的那些 "readline()"，因为我正在尝试读取 2 行并将它们存储在变量中...

该代码是我用来根据输入实际创建邻接矩阵和字典的代码输入数据的形式为：

304 #total number of vertex
1 #vertex number 0 has 1 neighbor
1 #the 1st neighbor o 0 is 1
1.067 # the value of the edge bteween 0 & 1 is 1.067
2 #vertex number 1 has 2 neighbors
0 #first neighbor is vertex 0
1.067 #value of edge is 1.067
2 #second neighbor is vertex 2
0.848 #value of edge is 0.848
2 #vertex 2 has 2 neighbors ...
1
0.848

因此，如果您想到更好的方式来读取文件或如何更正我的混合迭代问题！！

谢谢各位大佬！！

Answer 1

两种可能的解决方案： 1) 一个 while 循环，里面有所有 3 个 readlines

2) 你保留 for 循环并使用一个（或两个）变量来记住你处于哪个阶段

Python 2 阅读行问题

Python 2 readline issue

python

graph-theory