Python 如何将要分配给节点的数字的字母更改为数字？

我想知道如何在我的代码中将A（大写和小写）放入节点0中，但我真的不知道如何。我知道有chr，但我以前从未使用过它，我试着阅读和使用它，但我就是无法理解它

这是我的密码：

infinity = 1000000
invalid_node = -1

class Node:
    previous = invalid_node
    distFromSource = infinity
    visited = False

def populateNetwork(fileName):

    network = []
    networkFile = open(fileName, "r")
    for line in networkFile:
        network.append(map(int, line.strip().split(',')))
    return network

def populateNodeTable(network, StartNode):
    nodeTable = []
    for node in network:
        nodeTable.append(Node())
    nodeTable[StartNode].distFromSource = 0
    nodeTable[StartNode].visited = True
    return nodeTable

def nearestNeighbour(network, currentNode):
    neighbours = []
    column = 0
    for node in network[currentNode]:
        if node !=0:
            neighbours.append(column)
        column +=1
    return neighbours


def tentativeDistance(neighbours, network, nodeTable, currentNode):
    for neighbour in neighbours:
        if nodeTable[neighbour].visited == False:
            tentative = nodeTable[currentNode].distFromSource + network[currentNode][neighbour]
            if tentative < nodeTable[neighbour].distFromSource:
                nodeTable[neighbour].distFromSource = tentative
                nodeTable[neighbour].previous = currentNode
                print tentative

##Testing this Function
def newNodeTable(nodeTable):
    nextNode == invalid_node
    currentIndex = 0
    nextDestination == infinity
    for node in nodeTable:
        if node.visited == False and node.distanceFromSource < nextDestination:
            nextNode = currentIndex
            nextDestination = node.distanceFromSource
        currentIndex+=1
    return nextNode

##Testing this Function
def getRoute(routePath):
    getRoutePath = []
    getRouteFile = open(routePath, "r")
    for line in getRouteFile:
        getRoutePath.append(int,line.split(">"))
    return getRoutePath

network = populateNetwork('network.txt')
nodeTable = populateNodeTable(network, 1)
neighbours=nearestNeighbour(network, 1)
tentativeDistance(neighbours, network, nodeTable, 1)

print
print "Current nodes and visited"
for node in nodeTable:
    print node.previous, node.distFromSource, node.visited

##for line in network:
##    print line
print
print "Visual representation of the network array"
for index, val in enumerate(network):
    print index, val

我的route.txt文件基本上是“A>G”、“A>G”或“A>G”。

您可以使用文本

import string

print string.ascii_uppercase
# ABCDEFGHIJKLMNOPQRSTUVWXYZ

print string.ascii_lowercase
# abcdefghijklmnopqrstuvwxyz

print string.ascii_letters
# abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ

char = string.ascii_uppercase[0]  # A
char = string.ascii_uppercase[1]  # B
char = string.ascii_uppercase[2]  # C

char = string.ascii_lowercase[0]  # a
char = string.ascii_lowercase[1]  # b
char = string.ascii_lowercase[2]  # c

或者您可以使用

chr（number）

您可以使用

ord（字母）

---

如果你不介意的话，还有一个问题，我编写了以下代码：def getRoute（getRouteFile）：getRoutePath=[]routeFile=open（getRouteFile，“r”）对于routeFile中的路由：getRoutePath.append（map（ord，routes.split（'>'））返回getRoutePath，这对我很有用。如何使用这两个ascii数字来计算哪个最小或更大？

import string

print string.ascii_uppercase
# ABCDEFGHIJKLMNOPQRSTUVWXYZ

print string.ascii_lowercase
# abcdefghijklmnopqrstuvwxyz

print string.ascii_letters
# abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ

char = string.ascii_uppercase[0]  # A
char = string.ascii_uppercase[1]  # B
char = string.ascii_uppercase[2]  # C

char = string.ascii_lowercase[0]  # a
char = string.ascii_lowercase[1]  # b
char = string.ascii_lowercase[2]  # c

print chr(65 + 0) # A
print chr(65 + 1) # B
print chr(65 + 2) # C

print chr(97 + 0) # a
print chr(97 + 1) # b
print chr(97 + 2) # c

print ord('A') # 65
print ord('a') # 97