在python中有没有更简单的方法来做到这一点？

Question

我想试着找到一种更简单的方法来做到这一点，但我还没有找到任何方法。

这是一个可以写入的菜单。我正在尝试在文本中添加个性化的消息，以进一步使其更像人类，但是它似乎非常长，而且比它应该的更长。sandwich_t是询问用户是否想要三明治的问题，beverage是询问用户是否想要饮料的问题，等等。

if sandwich_t=="Yes" and beverage== "Yes" and fries== "Yes" and Ketchup== "Yes":
    print "Cashier: In total you have so far ordered a", sandwich, "sandwich, and a ", beverage_selection, "drink, with ", fries_selection, "fries, with ", Ketchup_Selection, "ketchup packets."
    print "Cashier: In total it will be $", total, "alright?"
    print "You: Alright"
if sandwich_t=="Yes" and beverage== "Yes" and fries== "Yes" and Ketchup== "No":
    print "Cashier: In total you have so far ordered a", sandwich, "sandwich, and a ", beverage_selection, "drink, with ", fries_selection, "fries, with no ketchup"
    print "Cashier: In total it will be $", total, "alright?"
    print "You: Alright"
if sandwich_t=="Yes" and beverage== "Yes" and fries== "No" and Ketchup== "Yes":
    print "Cashier: In total you have so far ordered a", sandwich, "sandwich, and a ", beverage_selection, "drink, with no fries, and ", Ketchup_Selection, "ketchup packets."
    print "Cashier: In total it will be $", total, "alright?"
    print "You: Alright"
if sandwich_t=="Yes" and beverage== "No" and fries== "Yes" and Ketchup== "Yes":
    print "Cashier: In total you have so far ordered a", sandwich, "sandwich, with no drink, with ", fries_selection, "fries, with ", Ketchup_Selection, "ketchup packets."
    print "Cashier: In total it will be $", total, "alright?"
    print "You: Alright"
if sandwich_t=="Yes" and beverage== "Yes" and fries== "No" and Ketchup== "No":
    print "Cashier: In total you have so far ordered a", sandwich, "sandwich, and a ", beverage_selection, "drink, with no fries, with no ketchup packets."
    print "Cashier: In total it will be $", total, "alright?"
    print "You: Alright"
if sandwich_t=="Yes" and beverage== "No" and fries== "No" and Ketchup== "No":
    print "Cashier: In total you have so far ordered a", sandwich, "sandwich, with no drink, with no fries, with ", Ketchup_Selection, "ketchup packets."
    print "Cashier: In total it will be $", total, "alright?"
    print "You: Alright"
if sandwich_t=="Yes" and beverage== "No" and fries== "Yes" and Ketchup== "No":
    print "Cashier: In total you have so far ordered a", sandwich, "sandwich, with no drink, with ", fries_selection, "fries, with no ketchup packets."
    print "Cashier: In total it will be $", total, "alright?"
    print "You: Alright"
if sandwich_t=="Yes" and beverage== "No" and fries== "No" and Ketchup== "Yes":
    print "Cashier: In total you have so far ordered a", sandwich, "sandwich, with no drink, with no fries, with", Ketchup_Selection, "ketchup packets."
    print "Cashier: In total it will be $", total, "alright?"
    print "You: Alright"
if sandwich_t=="No" and beverage== "Yes" and fries== "Yes" and Ketchup== "Yes":
    print "Cashier: In total so far you have no sandwich with a", beverage_selection, "drink with ", fries_selection, "fries and ", Ketchup_Selection, "ketchup packets."
    print "Cashier: In total it will be $", total, "alright?"
    print "You: Alright"
if sandwich_t=="No" and beverage== "Yes" and fries== "Yes" and Ketchup== "No":
    print "Cashier: In total so far you have no sandwich with a", beverage_selection, "drink with ", fries_selection, "fries with no ketchup packets."
    print "Cashier: In total it will be $", total, "alright?"
    print "You: Alright"
if sandwich_t=="No" and beverage== "Yes" and fries== "No" and Ketchup== "Yes":
    print "Cashier: In total so far you have no sandwich with a", beverage_selection, "drink no fries and ", Ketchup_Selection, "ketchup packets."
    print "Cashier: In total it will be $", total, "alright?"
    print "You: Alright"
if sandwich_t=="No" and beverage== "Yes" and fries== "No" and Ketchup== "No":
    print "Cashier: In total so far you have no sandwich with a", beverage_selection, "drink, no fries with no ketchup."
    print "Cashier: In total it will be $", total, "alright?"
    print "You: Alright"
if sandwich_t=="No" and beverage== "No" and fries== "Yes" and Ketchup== "Yes":
    print "Cashier: In total so far you have no sandwich with no drink, ", fries_selection, "fries with ", Ketchup_Selection, "ketchup packets."
    print "Cashier: In total it will be $", total, "alright?"
    print "You: Alright"
if sandwich_t=="No" and beverage== "No" and fries== "Yes" and Ketchup== "No":
    print "Cashier: In total so far you have no sandwich with no drink, ", fries_selection, "fries with no ketchup."
    print "Cashier: In total it will be $", total, "alright?"
    print "You: Alright"
if sandwich_t=="No" and beverage== "No" and fries== "No" and Ketchup== "Yes":
    print "Cashier: In total so far you have no sandwich, no drink, no fries, with ", Ketchup_Selection, "ketchup packets."
    print "Cashier: In total it will be $", total, "alright?"
    print "You: Alright"
if sandwich_t=="No" and beverage== "No" and fries== "No" and Ketchup== "No":
    print "Chasier: You ordered nothing. Why did you come here?"

Answer 1

您不能将字符串复制几十次，但可以逐个部分地构造它：

string = 'Cashier: In total so far'

if sandwich_t == 'Yes':
    string += ' ordered a '
    string += str(sandwich)
else:
    string += ' you have no sandwich'

if beverage == "Yes":
    string += ' with a '
    string += str(beverage_selection)
    string += ' drink'
else:
    string += 'no drink, '
# ... And another fries, drinks etc etc etc

print string
print "Cashier: In total it will be $", total, "alright?"
print "You: Alright"

Answer 2

Loops，你听说过它们吗？此外，非空的事物的计算结果为真。

假设番茄酱和薯条只是布尔值(不是带有"Yes“或”no“的字符串)，三明治要么是None，要么是带有名称的字符串(no "string_t")，类似的饮料：

cashier_text = "Cashier: In total you have so far ordered "
total = 0
if sandwich: # evaluates to true if string, skips if 
    cashier_text += sandwich
    cashier_text += " sandwich, and "
    total += #cost here, you don't have this in your code?
if beverage: # same as sandwich
    cashier_text += beverage
    total += #cost here, omitted in your code
if fries: # boolean
    cashier_text += " with fries"
    total += #cost here
if ketchup: #boolean
    cashier_text += " with additional ketchup"
#print cashier text here
#total and customer was always common so they should've been always here, not in if's

这更像是pythonic伪代码，而不是工作示例-它应该可以工作，但它会很难看，我直接在answer编辑器中编写了它。

在你想要的任何地方添加else，让句子变得有意义，这样如果没有什么东西就有意义了(就像我说的，我并不关心它--例如，如果你只用我的代码点三明治，它将是"name sandwitch，and")。

Answer 3

这是违反DRY (Don't Repeat Yourself)原则的一个很好的例子。你已经意识到这里有很多不幸的重复，干得好！

确实有一种更简单的方法来完成你想要的东西。作为一个额外的好处，它也将变得更干净和更易维护。

请注意，无论客户选择什么，打印的大部分字符串都是相同的。我们真的只想替换与他们的选择相对应的正确的关键短语。这是你可以做到的一种方法：

if sandwich_t=="No" and beverage== "No" and fries== "No" and Ketchup== "No":
    print("Chasier: You ordered nothing. Why did you come here?")
else:
    sandwich_message = "no sandwich"
    if sandwich_t == "Yes":
        sandwich_message = "a {sw} sandwich".format(sw=sandwich)

    beverage_message = "with no drink"
    if beverage == "Yes":
        beverage_message = "and a {bs} drink".format(bs=beverage_selection)

    fries_message = "with no fries"
    if fries == "Yes":
        fries_message = "with {fs} fries".format(fs=fries_selection)

    ketchup_message = "with no ketchup"
    if Ketchup == "Yes":
        ketchup_message = "with {ks} ketchup packets".format(ks=Ketchup_Selection)

    message = "Cashier: In total you have so far ordered {sm}, {bm}, {fm}, {km}.\n" \
              "Cashier: In total it will be ${total} alright?\n" \
              "You: Alright"

    print(message.format(
        sm=sandwich_message,
        bm=beverage_message,
        fm=fries_message,
        km=ketchup_message,
        total=total
    ))

编辑：还有一个注意事项:最好为变量名建立一个约定，并尽可能地遵守它。在你的例子中，你有一些小写的，带下划线的变量名(beverage_selection，fries_selection)，它们很好用！

尽量避免像Ketchup_Selection这样的名字。大写的变量名通常用于常量和类名。最好使用ketchup_selection。

还要记住，Python2是该语言的遗留版本，如果没有令人信服的理由继续使用Python2，那么您真的应该迁移到Python3。