Day8 Python学习笔记&关键注意点

 1 class Book:
 2     count = 0
 3 
 4     # Iniate the function
 5     def __init__(self,title,price=0.0,author=None):
 6         self.title = title
 7         self.price = price
 8         self.author = author
 9         Book.count += 1
10 
11     # Delete the object function
12     def __del__(self):
13         Book.count -= 1
14 
15     def __repr__(self):
16         return '<Book:{} at 0x{}>'.format(self.title,id(self))
17 
18     def __str__(self):
19         return '[Book:{},Price:{}]'.format(self.title,self.price)
20 
21     def print_info(self):
22         print(self.title,self.price,self.author)
23 
24     def cls_method(cls):
25         print('Class Function')
26 
27     # @static method
28     def static_method():
29         print('Static Function, have no relationship with instance in logic')
30 
31 
32 if __name__ == '__main__':
33     book = Book('Python Classic',price=29.0,author='Tom')
34     book2 = Book('Flask')
35     book3 = Book('ASP.net')
36 
37     # del(book3)
38 
39     # print('Book Number:{}'.format(Book.count))
40     # print('Book Number:{}'.format(book2.count))
41     #
42     # book2.count = 99
43     # print('Book Number:{}'.format(Book.count))
44     # print('Book Number:{}'.format(book2.count))
45 
46     Book.cls_method(book2)
47     Book.static_method()
48     # book2.static_method() #This will work if enable @staticmethod in line 27

 1 import datetime
 2 
 3 class Student:
 4 
 5     def __init__(self,name,birthdate):
 6         self.name = name
 7         # self.age = age
 8         self.birthdate = birthdate
 9 
10     @property
11     def age(self):
12         return datetime.date.today().year - self.birthdate.year
13 
14     @age.setter
15     def age(self,value):
16         raise AttributeError('Stop setting age!!!')
17 
18     @age.deleter
19     def age(self):
20         raise AttributeError('Cannot delete age!!!')
21 
22 
23     # def get_age(self):
24     #     return datetime.date.today().year - self.birthdate.year
25 
26 
27 if __name__ == '__main__':
28     s = Student('Tom',datetime.date(1992,3,1))
29     # print(s.age)
30     print(s.birthdate)
31     print(s.age)
32 
33     s.birthdate = datetime.date(1982,8,2)
34     # s.age = 20  #Cannot setting age that was defined in line 14-16
35     # print(s.birthdate)
36     # print(s.age)
37 
38     del(s.name)
39     print(s.name)
40 
41     # del(s.age)
42     # print(s.age) #Cannot delete age that was defined in line 18-20

 1 import math
 2 
 3 class Circle:
 4     def __init__(self,radius):
 5         self.radius = radius
 6 
 7     @property
 8     def area(self):
 9         return math.pi * self.radius **2
10 
11     #
12     # def get_area(self):
13     #     return math.pi * self.radius **2
14 
15 
16 c = Circle(4.0)
17 
18 print('Circle area is:{}'.format(c.area))

 1 # Sample 2: Ji Cheng
 2 import datetime
 3 
 4 class Department:
 5     def __init__(self,department,phone,manager):
 6         self.department = department
 7         self.phone = phone
 8         self.manager = manager
 9 
10     def __repr__(self):
11         return '<Department:{}>'.format(self.department)
12 
13 
14 class Employee:
15     def __init__(self,department:Department,name,birthdate,salary):
16         self.department = department
17         self.name = name
18         self.birthdate = birthdate
19         self.salary = salary
20 
21     @property
22     def age(self):
23         return datetime.date.today().year - self.birthdate.year
24 
25     def give_raise(self,percent,bonus=.0):
26         self.salary = self.salary * (1 + percent + bonus)
27 
28     def __repr__(self):
29         return'<Employee:{}>'.format(self.name)
30 
31     def working(self):
32         print('Employee:{},is working...'.format(self.name))
33 
34 
35 class Programer(Employee):
36     def __init__(self,department,name,birthdate,salary,specialty,project):
37         super().__init__(department,name,birthdate,salary)
38         self.specialty = specialty
39         self.project = project
40 
41     def working(self):
42         print('Programer:{} is developing a project:{}...'.format(self.name,self.project))
43 
44 
45 class HR(Employee):
46     def __init__(self,department,name,birthdate,salary,qualification_level=1):
47         Employee.__init__(self,department,name,birthdate,salary)
48         self.qualification_level = qualification_level
49 
50     def working(self):
51         print('HR:{} is interview new employee...'.format(self.name))
52 
53 
54 if __name__ == '__main__':
55     # p = Programer('R&D department','Peter',datetime.date(1990,3,3),8000.00,'Flask','CRM')
56     # print(p)
57     # print(p.department)
58     # print(p.salary)
59     # p.give_raise(.2,.1)
60     # print(p.salary)
61     # p.working()
62     # print(p.age)
63     #
64     # hr = HR('HR Department','Marry',datetime.date(1992,4,4),6000,qualification_level=3)
65     # hr.give_raise(.1)
66     # print(hr.salary)
67     # hr.working()
68 
69     dep = Department('R&D','010-87718391','Zhang da Shan')
70     p = Programer(dep,'Peter',datetime.date(1990,3,3),8000,'Python,Flask','Xmall')
71     p.give_raise(.2,.1)
72     print(p.salary)
73     print(p.department)
74     print(p.department.department)
75     print(p.department.phone)
76     print(p.department.manager)