最近在学习python，楼主练习写个程序遇到个问题，好像是全局变量的问题吧，我用return时能正常，但写GUI时不会用return了，结果读不进数据，有python高手请指导下。

普通程序：（能正常执行）
#读取路权矩阵
def readdata(D0,S0,D1,S1,list):
    fpr=open("d.txt")   
    k=0
    for line in fpr:
        k+=1
        D0[k]={}
        S0[k]={}
        S1[k]={}
        D1[k]={}
        list=line.split()
        for j in range(len(list)):
            D0[k][j+1]=int(list[j])
            S0[k][j+1]=j+1
            S1[k][j+1]=0
            D1[k][j+1]=0

    fpr.close()
    return (D0,S0,D1,S1,list)

#最短路算法
def solve(D0,S0,D1,S1,list):
    for k in range(1,len(list)+1):
        for k1 in range(1,len(list)+1):
            for j1 in range(1,len(list)+1):
                if D0[k1][j1]<=D0[k1][k]+D0[k][j1]:
                    S1[k1][j1]=S0[k1][j1]
                else:
                    S1[k1][j1]=S0[k1][k]
                D1[k1][j1]=min(D0[k1][j1],D0[k1][k]+D0[k][j1])
        if k<len(list):
            D0=D1
            S0=S1
    return (D0,S0,D1,S1,list)

#将路径和路权的结果写入文件中
def write_lujingluquan(D1,S1,list):
    fpw1=open("s1_res.txt","w+")
    fpw2=open("d1_res.txt","w+")
    for k in range(1,len(list)+1):
        for k1 in range(1,len(list)+1):
            fpw1.write("%d\t"%S1[k][k1])
            fpw2.write("%d\t"%D1[k][k1])
            if k1==len(list):
                 fpw1.write("\n")
                 fpw2.write("\n")

    fpw1.close()
    fpw2.close()

#将最短路结果写入文件中
def write_shortpath(D1,S1,list):
    fpw=open("solve.txt","w+")
    for k in range(1,len(list)+1):
        for k1 in range(1,len(list)+1):
            if k!=k1:
                fpw.write("%d->%d\t%d\t%d"%(k,k1,D1[k][k1],k))
                temp=k
                while S1[temp][k1]!=k1:
                    fpw.write("->%d"% S1[temp][k1])
                    temp=S1[temp][k1]
                fpw.write("->%d\n"%S1[temp][k1])

    fpw.close()

#查询
def research(k,k1):
    if k!=k1:
        print("  %d->%d\t  %d\t  %d"%(k,k1,D1[k][k1],k)),
        temp=k
        while S1[temp][k1]!=k1:
            print("->%d"% S1[temp][k1]),
            temp=S1[temp][k1]
        print("->%d"%S1[temp][k1])
    else:
        print("%d->%d\t%d\t%d->%d"%(k,k1,0,k,k1))


#函数入口
#初始化字典
D0={}
S0={}
S1={}
D1={}
list=[]
(D0,S0,D1,S1,list)=readdata(D0,S0,D1,S1,list)
(D0,S0,D1,S1,list)=solve(D0,S0,D1,S1,list)
write_lujingluquan(D1,S1,list)
write_shortpath(D1,S1,list)
a=input("查询两个节点的最短请输入1：")
if a==1:
    start=input("请输入起点：")
    end=input("请输入终点：")
    print "查询结果如下:"
    print "起终点\t最短路长\t路径"
    research(start,end)
#print "succeed!"


楼主想要GUI编程来实现，程序如下：（调试了下，好像不能把"d.txt"数据读进来，或者读了，等执行完readdata（）方法后又消失了）
#!/suer/bin/python
#-*-coding:UTF-8-*-
from Tkinter import *

#初始化字典
D0={}
S0={}
S1={}
D1={}
list=[]
app=Tk()

#读取路权矩阵
def readdata(D0,S0,D1,S1,list):
    fpr=open("d.txt")   
    k=0
    for line in fpr:
        k+=1
        D0[k]={}
        S0[k]={}
        S1[k]={}
        D1[k]={}
        list=line.split()
        for j in range(len(list)):
            D0[k][j+1]=int(list[j])
            S0[k][j+1]=j+1
            S1[k][j+1]=0
            D1[k][j+1]=0

    fpr.close()
    #return (D0,S0,D1,S1,list)

#最短路算法
def solve(D0,S0,D1,S1,list):
    for k in range(1,len(list)+1):
        for k1 in range(1,len(list)+1):
            for j1 in range(1,len(list)+1):
                if D0[k1][j1]<=D0[k1][k]+D0[k][j1]:
                    S1[k1][j1]=S0[k1][j1]
                else:
                    S1[k1][j1]=S0[k1][k]
                D1[k1][j1]=min(D0[k1][j1],D0[k1][k]+D0[k][j1])
        if k<len(list):
            D0=D1
            S0=S1
    return (D0,S0,D1,S1,list)

#将路径和路权的结果写入文件中
def write_lujingluquan(D1,S1,list):
    fpw1=open("s1_res.txt","w+")
    fpw2=open("d1_res.txt","w+")
    for k in range(1,len(list)+1):
        for k1 in range(1,len(list)+1):
            fpw1.write("%d\t"%S1[k][k1])
            fpw2.write("%d\t"%D1[k][k1])
            if k1==len(list):
                 fpw1.write("\n")
                 fpw2.write("\n")

    fpw1.close()
    fpw2.close()

#将最短路结果写入文件中
def write_shortpath(D1,S1,list):
    fpw=open("solve.txt","w+")
    for k in range(1,len(list)+1):
        for k1 in range(1,len(list)+1):
            if k!=k1:
                fpw.write("%d->%d\t%d\t%d"%(k,k1,D1[k][k1],k))
                temp=k
                while S1[temp][k1]!=k1:
                    fpw.write("->%d"% S1[temp][k1])
                    temp=S1[temp][k1]
                fpw.write("->%d\n"%S1[temp][k1])

    fpw.close()

#查询
def research(k,k1):
    if k!=k1:
        print("  %d->%d\t  %d\t  %d"%(k,k1,D1[k][k1],k)),
        temp=k
        while S1[temp][k1]!=k1:
            print("->%d"% S1[temp][k1]),
            temp=S1[temp][k1]
        print("->%d"%S1[temp][k1])
    else:
        print("%d->%d\t%d\t%d->%d"%(k,k1,0,k,k1))


b1=Button(app,text="读取数据",command=lambda:readdata(D0,S0,D1,S1,list)).pack()
b2=Button(app,text="算法",command=lambda:solve(D0,S0,D1,S1,list)).pack()
b3=Button(app,text="write_lujingluquan",command=lambda:write_lujingluquan(D1,S1,list)).pack()
b4=Button(app,text="write_shortpath",command=lambda:write_shortpath(D1,S1,list)).pack()
app.mainloop()