变量与数据属性

class Chinese:
   '''这依旧是一个中国人的类'''
   country = 'china'
   def __init__(self, name):
      self.name = name

   def play_ball(self, ball):
      print('%s正在打%s' % (self.name, ball))

p1 = Chinese('alex')
print(p1.country)
p1.country = 'hongkang' # 这里是增加的实例属性
print(Chinese.country) # 'china'
print(p1.country) # 'hongkang'


country1 = 'china'
class Chinese1:
   '''这依旧是一个中国人的类'''
   def __init__(self, name):
      self.name = name

   def play_ball(self, ball):
      print('%s正在打%s' % (self.name, ball))

p2 = Chinese1('sb')
# print(p2.country1) # 会报错，只在类里面找，不会去外面找


country2 = 'china'
class Chinese2:
   '''这依旧是一个中国人的类'''
   def __init__(self, name):
      self.name = name
      print(country2) # 打印的是'china'，这样的变量引用没有用.所以只能在类外边去找

   def play_ball(self, ball):
      print('%s正在打%s' % (self.name, ball))

p3 = Chinese2('alex')


country3 = 'china'
class Chinese3:
   '''这依旧是一个中国人的类'''
   country3 = 'shenzhen'
   def __init__(self, name):
      self.name = name
      print(country3) # 打印的是'china'
      print(Chinese3.country3) # 变量引用用了.所以打印的是'shenzhen'
   def play_ball(self, ball):
      print('%s正在打%s' % (self.name, ball))

p4 = Chinese3('alex')