Python为类定义“拷贝构造函数”

初学Python，这么做好像有点2，凑合能用：

class MyClass(): def __init__(self, n = 10): self._Field = n def __getitem__(self, range): return MyClass(self._Field)obj1 = MyClass()obj2 = obj1obj3 = obj1[:]obj1._Field = 100obj4 = MyClass(123)print obj1._Field, obj2._Field, obj3._Field, obj4._Field 

实际输出为：

>>> 100 100 10 123