Question

因为我是python编程语言和OOP概念的新手。我正在锻炼班级和目标代码。虽然我收到了这个错误

AttributeError：类型对象'Employee'没有属性'empCount'“

class Employee:

    def __init__(self, name, salary):
        self.name = name
        self.salary = salary
        Employee.empCount = Employee.empCount + 1 

    def DisplayCount(self):
        print("Total Employee %d" % Employee.empcount)

    def DisplayEmployee(self):
        print("Name:",self.name," Salary:",self.salary)

码

emp1 = Employee("Zara", 1000)
emp2 = Employee("Brad", 1500)

emp1.DisplayEmployee()
emp2.DisplayEmployee()
print("Total Employee %d" % Employee.empCount)`emp1 = Employee("Zara", 1000)
emp2 = Employee("Brad", 1500)

emp1.DisplayEmployee()
emp2.DisplayEmployee()
print("Total Employee %d" % Employee.empCount)`

谁能告诉我这里有什么问题？解释。

Answer 1

问题是Employee.empCount尚未在班级定义，而您正试图访问它。如果您的目的是根据创建的实例计算一个tap员工数，那么像这样的类变量就可以了。但是，通常不建议以这种方式跨实例共享变量，而是建议找到可靠的替代方案。

注意类Employee继承自object，这在Python中称为新样式类。

In [29]: 
class Employee(object):
    empCount = 0

    def __new__(cls, *args, **kwargs):
        cls.empCount += 1
        return super(Employee, cls).__new__(cls, *args, **kwargs)

    def __init__(self, name, salary):
        self.name = name
        self.salary = salary

    def DisplayCount(self):
        print("Total Employee %d" % Employee.empcount)

    def DisplayEmployee(self):
        print("Name:",self.name," Salary:",self.salary)
## -- End pasted text --

In [30]: emp1 = Employee("Zara", 1000);emp2 = Employee("Brad", 1500)

In [31]: emp1.empCount
Out[31]: 2

In [32]: emp3 = Employee("Tes", 100)

In [33]: emp1.empCount
Out[33]: 3

Answer 2

在__init__中，您正在尝试访问不存在的类变量：

Employee.empCount = Employee.empCount + 1 
#                   ^^^^^^^^^^^^^^^^^ what's the initial value?

您需要在类级别定义变量，以便对变量进行后续更新，并且python区分大小写，因此您需要修复DisplayCount中的下一个错误：

class Employee:
     empCount = 0
     ...

    def DisplayCount(self):
         print("Total Employee %d" % Employee.empCount)
         #                                     ^^^^^

Answer 3

您需要设置'Employee.empCount'变量。

def __init__(self, name, salary):
self.name = name
self.salary = salary
Employee.empCount = 0
Employee.empCount = Employee.empCount + 1

这应该有效。

Answer 4

您的问题是您正在尝试计算员工班级中的员工人数。这就像每个员工都知道总数...

每次创建员工时，您必须拥有一种可以计算员工数量的类，或者最简单的方法是将员工存储在列表中，然后查看列表的大小。

解决方案可能是：

class Employee:

    def __init__(self, name, salary):
        self.name = name
        self.salary = salary

    def DisplayEmployee(self):
        print("Name:",self.name," Salary:",self.salary)

代码：

employees = []
employees.append(Employee("Zara", 1000))
employees.append(Employee("Brad", 1500))

[e.DisplayEmployee() for e in employees]
print("Total Employee %d" % len(employees))

导致：

Name: Zara  Salary: 1000
Name: Brad  Salary: 1500
Total Employee 2

希望能够帮助你。

AttributeError：类型对象'Employee'没有属性'empCount'

4 个答案: