集合与委托格式说明符

#!/usr/bin/env python
# -*- coding:‘uft-8‘ -*-

class Student(object):
	def __init__(self,name=None,gender=None):
		self.name,self.gender=name,gender

	def __format__(self,pattern):
		return ‘{}(name={name!r},gender={gender!r})‘.format(self.__class__.__name__, 
			**self.__dict__)

class Class_(object):
	def __init__(self,*students):
		self.__student=students

	def __format__(self,pattern):
		return ‘{}({})‘.format(Class_.__name__, 
			‘,‘.join(format(_,pattern) for _ in self.__student))


s1=Student(‘Jan‘,‘Fmale‘) 
s2=Student(‘Mike‘,‘male‘)
a_instance_class=Class_(s1,s2)
print format(a_instance_class,‘‘)
a_instance_class1=eval(format(a_instance_class,‘‘))