l1.py

file1 = open(r"C:\Users\ming\Desktop\test.txt",'r',encoding='utf-8')
for data in file1:
    if data == "小强：10本\n":
        print("找到了")
file1.close()

a = "0123456789"
index_in = int(input("请输入下标："))
try:
    print(a[index_in])
except:
    print(a[-1])