python2.7 select data file to rerun file

Question

I am running a python/pygame game that i need to get a 'txt' data file from a previouse running of the game. 'save1.txt' I have many files save....txt i need to be able to select 1 from a list possibly using tkinter askdialog to update the value of 'y' in the code snip. all the code is in the same directory

I nave been searching SO but can not find a suitable example

y = 'save1.txt'
R=[0]*10
inputFile = (y,'r') #open(y , 'rb')

for i in range(0,10):
    R[i] = pickle.load(inputFile)


inputFile.close()
for i in range(0,10):
        if R[i]== 0:
        print i,'ii'
        S=i-1
    else:
        S = 3