Python的deepcopy（）的Decimal（）对象(Python deepcopy() of a Decimal() object)

 我努力深度拷贝（）一个包含Decimal值的类。 所以我尝试了深度复制一个Decimal对象，并且失败了。 我在这里误解了什么？ 
 
from copy import deepcopy
from decimal import Decimal

## Deepcopy an array ##
a = [1,2,3,4]
b = deepcopy(a)
a is b
# False

## Deep copy a Decimal ##
a = Decimal('0.123')
b = deepcopy(a)
a is b
# True

## Deepcopy a class containing a Decimal ##
class A(object):
    def __init__(self, dec):
        self.myDecimal = Decimal(dec)

a = A('0.123')
b = deepcopy(a)
a is b
# False

a.myDecimal is b.myDecimal
# True
 
 该类复制但小数引用保持不变。 

I'm struggling to deepcopy() a class containing a Decimal value. So I tried deep copying a Decimal object on its own and that failed too. What am I misunderstanding here?
 
from copy import deepcopy
from decimal import Decimal

## Deepcopy an array ##
a = [1,2,3,4]
b = deepcopy(a)
a is b
# False

## Deep copy a Decimal ##
a = Decimal('0.123')
b = deepcopy(a)
a is b
# True

## Deepcopy a class containing a Decimal ##
class A(object):
    def __init__(self, dec):
        self.myDecimal = Decimal(dec)

a = A('0.123')
b = deepcopy(a)
a is b
# False

a.myDecimal is b.myDecimal
# True
 
The class copies but the decimal reference remains the same.

原文：https://stackoverflow.com/questions/43369382