使用类时如何修复属性错误

Question

编写一个名为“Person”的 class，其中包含人名、地址和电话号码的数据属性。

class Person:
    def __init__(self, n, a, p):
        self.name = n
        self.address = a
        self.phone = p
    
    def set_name(self, n):
        self.name = n
    
    def set_address(self, a):
        self.address = a
    
    def set_phone(self, p):
        self.phone = p
    
    def get_name(self):
        return 'Customer Name:'
    
    def get_address(self):
        return 'Customer Address:'
    
    def get_phone(self):
        return 'Customer Phone Number:'
    
def main():
    n = input('Enter Customer Name: ')
    a = input('Enter the Customer Address: ')
    p = input('Enter the Customer Phone Number: ')
    
    print(n.get_person())
    print(a.get_address())
    print(p.get_phone())
main()

如何修复我的属性错误？

Answer 1

首先，您的错误确实应该是TypeError ，因为您正在从 class 调用实例方法：

>>> class Foo:
...     def __init__(self):
...         self.bar = 1
...     def thing(self):
...         return self.bar
...
>>>
>>>
>>> Foo.thing()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: thing() missing 1 required positional argument: 'self'

但是，无论如何修复都是相同的。

您需要创建一个 class 的实例来访问其属性：

class Foo:
    def __init__(self):
        self.bar = 1

# Foo is a class, but it doesn't have a 
# bar attribute. An *instance* of the class
# does

# this raises an attributeError
Foo.bar
AttributeError

# this doesn't, because we created an instance
foo = Foo()
foo.bar
1

您需要创建一个 person 实例，然后您可以获取它的属性：

class Person:
    def __init__(self, name, address, phone):
        self.name = name
        self.address = address
        self.phone = phone


Person.phone 
# AttributeError

# Create an instance of Person here
tim = Person(name='Tim', address='1234 Main St', phone='555-5555')

# Then you can get Tim's information
tim.phone
'555-5555'

Answer 2

您需要使用person = Person(n, a, p)之类的东西创建 Person class 的实例。 在main() function 的输入语句之后执行此操作。

其次，在打印出属性时，您需要引用您创建的 Person class 的实例（即 person.get_person()、person.get_address() 等）。

最后，在调用 get function 时，请确保这些函数返回您要查找的值。 function get_address()应该返回 self.address。

这是我的建议：

class Person:
    def __init__(self, n, a, p):
        self.name = n
        self.address = a
        self.phone = p
    
    def set_name(self, n):
        self.name = n
    
    def set_address(self, a):
        self.address = a
    
    def set_phone(self, p):
        self.phone = p
    
    def get_name(self):
        return self.name
    
    def get_address(self):
        return self.address
    
    def get_phone(self):
        return self.phone

def main():
    n = input('Enter Customer Name: ')
    a = input('Enter the Customer Address: ')
    p = input('Enter the Customer Phone Number: ')
    
    person = Person(n, a, p) # create the instance

    # get attributes of instantiated object
    print(person.get_person())
    print(person.get_address())
    print(person.get_phone())

main()