我怎样才能让这个用户更友好？

Question

print ("Address book")
print ("~~~~~~~~~~~~~")
print ("Welcome to your address book")

yn = ""

while yn != "n":
    yn = input ("Would you like to search for a user? (Y/N) ")

    if yn == "y":
        search = input ("Would you like to search by surname (S) or month of birth (M) ")

        if search.lower() == "s":
            surname = input ("Please enter the surname: ")
            for line in open("datafile.txt"):
                if surname in line:
                    print(line)


        elif search.lower() == "m":
            DMY = input("please enter your date of birth you are looking for (date/month/year) : ")
            DMY = DMY.split("/")
            DMY = DMY[1]

            for line in open("datafile.txt"):
                if DMY in line:
                    print(line)
        else:
            print ("Sorry you can not do this please try again.")
    elif yn == "n":
        print("Goodbye")
    else:
        print("Sorry you can not do this please try again.")

Answer 1

尝试打印（“欢迎使用地址簿，这会搜索姓氏或地址。”）