python编程普通及类和静态方法示例详解

import sys
sys.version

class Student(object):
    num_of_stu = 0 #学生人数
    def __init__(self, name, age, math, Chinese):
        self.name = name #学生姓名
        self.age = age #学生年龄
        self.math = math #数学成绩
        self.Chinese = Chinese #语文成绩
        Student.num_of_stu += 1 #每实例化一个学生，人数加1，相当于静态变量
    def __del__(self):
        Student.num_of_stu -= 1 #每删除一个实例，人数减1
    #普通方法，用于计算学生的总分
    def total_score(self):
        return self.math + self.Chinese

print (Student.num_of_stu)
stu1 = Student('Bob', 11, 51, 33)
print (stu1.total_score())
stu2 = Student('Peco', 12, 98, 79)
print (stu2.total_score())
print (Student.num_of_stu)
del stu1
print (Student.num_of_stu)

class Student(object):
    num_of_stu = 0 #学生人数
    def __init__(self, name, age, math, Chinese):
        self.name = name #学生姓名
        self.age = age #学生年龄
        self.math = math #数学成绩
        self.Chinese = Chinese #语文成绩
        Student.num_of_stu += 1 #每实例化一个学生，人数加1，相当于静态变量
    def __del__(self):
        Student.num_of_stu -= 1 #每删除一个实例，人数减1
    #普通方法，用于计算学生的总分
    def total_score(self):
        return self.math + self.Chinese
    #类方法，用于用字符串生成实例
    @classmethod
    def from_string(cls, stu_str):
        name, age, math, Chinese = stu_str.split('-')
        return cls(name, int(age), float(math), float(Chinese))

stu_str = "Bob-12-50-34"
stu1 = Student.from_string(stu_str)
print (stu1.name, stu1.total_score())

class Student(object):
    num_of_stu = 0 #学生人数
    def __init__(self, name, age, math, Chinese):
        self.name = name #学生姓名
        self.age = age #学生年龄
        self.math = math #数学成绩
        self.Chinese = Chinese #语文成绩
        Student.num_of_stu += 1 #每实例化一个学生，人数加1，相当于静态变量
    def __del__(self):
        Student.num_of_stu -= 1 #每删除一个实例，人数减1
    #普通方法，用于计算学生的总分
    def total_score(self):
        return self.math + self.Chinese
    #类方法，用于用字符串生成实例
    @classmethod
    def from_string(cls, stu_str):
        name, age, math, Chinese = stu_str.split('-')
        return cls(name, int(age), float(math), float(Chinese))
    #静态方法，用于判断要不要上学
    @staticmethod
    def is_school_day(day):
        if day.weekday() == 5 or day.weekday() == 6:
            return False
        return True

import datetime
my_date1 = datetime.date(2017, 9, 15)
my_date2 = datetime.date(2017, 9, 16)
print (Student.is_school_day(my_date1))
print (Student.is_school_day(my_date2))