元类
- Python中类也是对象。
- 负责生成其它类的类就是元类。
- 可以通过使用type而非class创建类
- 元类继承type
def init(self, name):
self.name = name
def run(self):
print '%s is runing' % self.name
Student = type('Student', (object,), {
'__doc__': 'Student Info Class',
'__init__': init,
'run': run,
})
s = Student('Ban')
s.run()
class MetaClass(type):
def __new__(cls, name, bases, attrs):
print "do soming before Class def"
for key, value in attrs.items():
print "[%s:%s]" % (key, value)
return super(MetaClass, cls).__new__(cls, name, bases, attrs)
class Person(object):
__metaclass__ = MetaClass
def __init__(self, name):
self.name = name
print "Person __init__"
def test(self):
print 'test %s' % self.name
def teach(self):
print '%s is teaching' % self.name
Teacher = MetaClass('Teacher', (Person,), {
'teach': teach,
})