Question

我想将此函数的date2追加到

def date_register():
     print("Enter date of registration")
     year = int(input("Enter a year: "))
     month = int(input("Enter a month: "))
     day = int(input("Enter a day: "))
     date1 = datetime.date(year,month,day)
     date2 = date1 + timedelta(days = 140)
     print("Check out date:",date2)

这个函数和它出来了date2没有定义

def update_A(row):  #to update the roomA
    if len(roomA[row]) < 2: #if roomA is less than 2
        name = input("Enter your name here: ")
        print(date_register())
        roomA[row].append((name,date2))
        print("Your room no. is {} at row {}".format(roomA[row].index((name,date2))+1,row))
        print(Continue())

寻求帮助谢谢

Answer 1

date2未定义，因为它不在update_A的范围内有关范围的更多信息，请阅读here。

您似乎也在混淆return和print

在update_A，您可以写print(date_register())，但date_register不会返回任何要打印的内容。

print将字符串表示发送到控制台，不能用于分配。而是使用return基本上强制函数调用解析为return语句旁边的值。例如：

def foo:
    return "bar"
print(foo())

调用foo时，它将解析为"bar"，然后将其打印到控制台。有关print()和return的差异和用法的更多信息，请参阅here

要在date2中使用update_A，您应该将其返回并按如下方式分配：

def date_register():
     print("Enter date of registration")
     year = int(input("Enter a year: "))
     month = int(input("Enter a month: "))
     day = int(input("Enter a day: "))
     date1 = datetime.date(year,month,day)
     date2 = date1 + timedelta(days = 140)
     print("Check out date:",date2)
     return date2 
def update_A(row):  #to update the roomA
    if len(roomA[row]) < 2: #if roomA is less than 2
        name = input("Enter your name here: ")
        date2 = date_register() #assign date2 returned value
        print(date2)
        roomA[row].append((name,date2))
        print("Your room no. is {} at row {}".format(roomA[row].index((name,date2))+1,row))
        print(Continue())

Answer 2

我已经纠正了一两个其他小错误。

import datetime

def date_register():
    print("Enter date of registration")
    year = int(input("Enter a year: "))
    month = int(input("Enter a month: "))
    day = int(input("Enter a day: "))
    date1 = datetime.date(year,month,day)
    date2 = date1 + datetime.timedelta(days = 140)
    print("Check out date:",date2)
    return date2

def update_A(row):  #to update the roomA
    if len(roomA[row]) < 2: #if roomA is less than 2
        name = input("Enter your name here: ")
        checkout_date = date_register()
        print(checkout_date)
        roomA[row].append((name,checkout_date))
        print("Your room no. is {} at row {}".format(roomA[row].index((name,checkout_date))+1,row))

roomA = {1: []}
update_A(1)

这是输出。

Enter your name here: John
Enter date of registration
Enter a year: 1954
Enter a month: 7
Enter a day: 12
Check out date: 1954-11-29
1954-11-29
Your room no. is 1 at row 1

显然，你需要弄清楚如何打印退房日期。

如何从另一个函数python3追加一个变量

2 个答案: