Question

您好我正在尝试使用课程打印4个乐队成员的详细信息，但是我只能打印一个，生病的样本给你一个理解，这是我的整个代码

class Person:
    def __init__(self, _firstname, _surname, d, m, y):
        self._firstname = _firstname
        self._surname = _surname
        self.d = d
        self.m = m
        self.y = y

    def __repr__(self):
        return '{} {} \n{} {} {}'.format(john._firstname, john._surname, john.d, john.m, john.y)
        return '{} {} \n{} {} {}'.format(paul._firstname, paul._surname,     paul.d, paul.m, paul.y)
        return '{} {} \n{} {} {}'.format(george._firstname,     george._surname, george.d, george.m, george.y)
        return '{} {} \n{} {} {}'.format(ringo._firstname, ringo._surname,     ringo.d, ringo.m, ringo.y)

john = Person('John','Lennon','8th','October','1940')
paul = Person('Paul','McCartney','18th','June','1942')
george = Person('George','Harrison','25th','February','1943')
ringo = Person('Ringo','Starr','7th','July','1940')


john._firstname = 'John'
john._surname = 'Lennon'
john.d = '8th'
john.m = 'October'
john.y = '1940'


paul._firstname = 'Paul'
paul._surname = 'McCartney'
paul._d = '18th'
paul._m = 'June'
paul._y = '1942'

george._firstname = 'George'
george._surname = 'Harrison'
george._d = '25th'
george._m = 'February'
george._y = '1943'

ringo._firstname = 'Ringo'
ringo._surname = 'Starr'
ringo._d = '7th'
ringo._m = 'July'
ringo._y = '1940'

print('{} {} \n{} {} {}'.format(john._firstname, john._surname, john.d, john.m, john.y))
print('{} {} \n{} {} {}'.format(paul._firstname, paul._surname, paul.d,     paul.m, paul.y))
print('{} {} \n{} {} {}'.format(george._firstname, george._surname,         george.d, george.m, george.y))
print('{} {} \n{} {} {}'.format(ringo._firstname, ringo._surname,     ringo.d,     ringo.m, ringo.y))

我收到了正确的输出，这是：

John Lennon
8th October 1940
Paul McCartney 
18th June 1942
George Harrison 
25th February 1943
Ringo Starr 
7th July 1940

我希望能够输入：

print(john)
print(george)
print(paul)
print(ringo)

要获得相同的输出，但是当我输入并删除底部的4条打印行时，我得到了这个

John Lennon 
8th October 1940
John Lennon 
8th October 1940
John Lennon 
8th October 1940
John Lennon 
8th October 1940

到目前为止，我的理解是__repr__(self)只能读取一行代码，即john，但这就是我知识停止的地方。

任何帮助都非常感谢！如果您需要更多信息，请问我，我在大学的第一年就是新手，所以感谢您的耐心和帮助！:)

Answer 1

任何return命令都会退出该函数，因此在同一级别拥有多个return命令将无法在Python中运行。

您的代码存在的问题是，您应该在self定义中使用关键字__repr__，这样您就可以使用

创建的所有四个实例访问它

john = Person('John','Lennon','8th','October','1940')
paul = Person('Paul','McCartney','18th','June','1942')
george = Person('George','Harrison','25th','February','1943')
ringo = Person('Ringo','Starr','7th','July','1940')

类Person实例的创建也会自动存储您输入的所有信息，因此无需为john._firstname等手工指定值。

要给出明确答案：

class Person:
    def __init__(self, _firstname, _surname, d, m, y):
        self._firstname = _firstname
        self._surname = _surname
        self.d = d
        self.m = m
        self.y = y

    def __repr__(self):
        return '{} {} \n{} {} {}'.format(self._firstname,
                                         self._surname,
                                         self.d,
                                         self.m,
                                         self..y)

john = Person('John','Lennon','8th','October','1940')
paul = Person('Paul','McCartney','18th','June','1942')
george = Person('George','Harrison','25th','February','1943')
ringo = Person('Ringo','Starr','7th','July','1940')

print(john)
print(paul)
print(george)
print(ringo)

Answer 2

您的__repr__讨论类john等类实例。需要编写它以满足任何 Person的实例。

def __repr__(self):
    return '{} {} \n{} {} {}'.format(self._firstname, self._surname, self.d, self.m, self.y)

Answer 3

你留下一个带有return语句的函数。以下行被忽略。在访问属性的方法中，您只使用对象本身的占位符。使用self代替对象的真实姓名。

def __repr__(self): 
  return '{} {} \n{} {} {}'.format(
    self._firstname, self._surname, self.d, self.m, self.y)

打印课程

3 个答案: