python代码输出的结果是方法对应的地址或指针，而不是具体的内容，怎么把这个实例输出出来？
>>> from _ctypes import PyObj_FromPtr as getVal
>>> a = 1.515
>>> b = 'abcde'
>>> c = [1,2,3,5]
>>> address1 = id(a)
>>> address2 = id(b)
>>> address3 = id(c)
>>> getVal(address1)
1.515
>>> getVal(address2)
'abcde'
>>> getVal(address3)
[1, 2, 3, 5]
了解一个对象的__str__方法
可以重写自定义类的__repr__ 方法