可视化对象(str/repr/bytes)

• __repr__ 对应repr(object)这个函数，返回一个可以用来表示对象的可打印字符串
• __str__ 对应str(object)这个函数，返回一个字符串对象，适合用于print输出
• __bytes__ 对应bytes(object)这个函数，返回bytes对象

class B:
    def __init__(self,name):
        self.name = name
        
    def __repr__(self):
        return 'call __repr__ name is {0}'.format(self.name)
    
    def __str__(self):
        return 'call __str__ name is {0}'.format(self.name)
    
    def __bytes__(self):
        return 'call __bytes__ name is {0}'.format(self.name).encode('utf-8')

 b = B('zhaochj') 

b 
call __repr__ name is zhaochj 

print(b)
call __str__ name is zhaochj

str(b)
'call __str__ name is zhaochj'

bytes(b)
b'call __bytes__ name is zhaochj'