Python-从出生日期获取员工年龄的类？

问题描述

import datetime
class Employee:
    def __init__ (self,first,last,pay,dob):
        self.first = first
        self.last = last
        self.pay = pay
        self.email = first + "." + last + "@company.com"
        self.dob = dob
    
    def fullname(self):
        return '{} {}'.format(self.first,self.last)
    
    def age(dob):
        today = date.today()
        return today.year - dob.year - ((today.month,today.day) < (dob.month,dob.day))
         
    
emp1 = Employee("aa","ss",122,date(1991,2,3))
emp2 = Employee("ww","ii",637,date(1997,8,24))
emp3 = Employee("ee","oo",986,date(1986,10,19))

#driver code
print(Employee.age(emp2))

我收到以下错误：

AttributeError：“雇员”对象没有属性“年份”

这有什么不对？

解决方法

您的Employee.age()方法签名只有一个参数-dob。调用它时，传递的第一个参数是实例。按照约定，我们使用参数self。但是您使用dob。遵循惯例，就像使用其他方法一样。然后使用self.dob.year

from datetime import date
class Employee:
    def __init__ (self,first,last,pay,dob):
        self.first = first
        self.last = last
        self.pay = pay
        self.email = first + "." + last + "@company.com"
        self.dob = dob
    
    @property
    def fullname(self):
        return '{} {}'.format(self.first,self.last) # in 3.6 return f'{self.first} {self.last}'
    
    def age(self):
        today = date.today()
        return today.year - self.dob.year - ((today.month,today.day) < (self.dob.month,self.dob.day))
         
    
emp1 = Employee("aa","ss",122,date(1991,2,3))
emp2 = Employee("ww","ii",637,date(1997,8,24))
emp3 = Employee("ee","oo",986,date(1986,10,19))

#driver code
print(emp1.age())

注意，我还添加了@property装饰器，因此全名是“只读”属性 并修复了导入

在3.6及更高版本中，您可以使用f字符串。 age和e-mail property，例如fullname可能是只读属性（即，您不应该指定与dob相矛盾的年龄），例如

@property
def age(self):
    today = date.today()
    return today.year - self.dob.year - ((today.month,self.dob.day))

然后您可以像这样使用它

print(emp1.age) # note the difference when it is method in the original class,and now when its property
     

,

您的employee类没有年份属性

但是

employee.dob拥有

import datetime
from datetime import date
class Employee:
    def __init__ (self,dob):
        self.first = first
        self.last = last
        self.pay = pay
        self.email = first + "." + last + "@company.com"
        self.dob = dob
    
    def fullname(self):
        return '{} {}'.format(self.first,self.last)
    
    def age(dob):
        today = date.today()
        dob = dob.dob # get dob from the object(of employee class) <<<<< Single change
        return today.year - dob.year - ((today.month,today.day) < (dob.month,dob.day))
         
    
emp1 = Employee("aa",19))

#driver code
print(Employee.age(emp2))