python - 当我运行程序时，为什么 python 会出现错误“需要缩进 block ？”

Question

我试图让我的程序限制用户可以输入的内容。它不断从下面的代码返回“预期缩进 block ”错误。

deliverydetails = input("Is your order for delivery?\n Press 1 for delivery. Press 2 for pickup")

if deliverydetails == "1":

##    def delivery ():

    print ("Order for Delivery")
    customerfirstname = " "
    while len(customerfirstname) <3 or len(customerfirstname)>30 or customerfirstname.isalpha() != True:
    customerfirstname = input("Customer First Name: ** must be 4 characters long  + " ")                         
    while len(customersurname) < 3 or len(customersurname) > 30 or     customerfirstname.isalpha() != True:                        
    customersurname = input("Customer Surname:" + " ")
    customerstreet = input("Street name:" + " ")
    customerstreetnumber = input("Street number:" + " ")
    customercity = input("City:" + " ")
    customersuburb = input("Suburb (If none, leave blank):" + " ")
    latestOrder.append(customerfirstname)
    latestOrder.append(customersurname)
    latestOrder.append(customerstreet)
    latestOrder.append(customerstreetnumber)
    latestOrder.append(customercity)
    latestOrder.append(customersuburb)

Answer 1

Python 使用缩进对代码块进行分组。在 while 语句之后，您需要缩进其下方应在 while 循环内执行的行。

以下是一些可能有用的其他提示:- 使用 pylint 检查你的语法。它将发现许多错误，否则您只能在运行时发现这些错误。- 使用空格来缩进。不要使用选项卡。这是 PEP 8 风格的推荐

这是代码的更正版本:

deliverydetails = input("Is your order for delivery?\n Press 1 for delivery. Press 2 for pickup")

if deliverydetails == "1":
##    def delivery ():
    print ("Order for Delivery")
    customerfirstname = " "
    customersurname = " "

    while len(customerfirstname) <3 or len(customerfirstname)>30 or customerfirstname.isalpha() != True:
        customerfirstname = input("Customer First Name: ** must be 4 characters long  + " ")                         

    while len(customersurname) < 3 or len(customersurname) > 30 or     customerfirstname.isalpha() != True:                        
        customersurname = input("Customer Surname:" + " ")

    customerstreet = input("Street name:" + " ")
    customerstreetnumber = input("Street number:" + " ")
    customercity = input("City:" + " ")
    customersuburb = input("Suburb (If none, leave blank):" + " ")
    latestOrder.append(customerfirstname)
    latestOrder.append(customersurname)
    latestOrder.append(customerstreet)
    latestOrder.append(customerstreetnumber)
    latestOrder.append(customercity)
    latestOrder.append(customersuburb)