python有個內建的copy的模組專門用於處理深拷貝與淺拷貝，很實用，用起來也很方便，能為我們省去不少麻煩，不用自己再寫深拷貝或者淺拷貝物件的方法了。
賦值，淺拷貝，深拷貝只針對可變變數，如list，dict,tuple
python中賦值都是進行記憶體位址的傳遞
淺拷貝(copy,copy())只會賦值物件，重新申請記憶體位址，但對於物件中的元素依然是原始的記憶體位址引用
如果要完全拷貝乙個物件，請使用copy.deepcopy()
#coding=utf-8
from copy import copy, deepcopy
if __name__ ==
"__main__"
:print
('deepcopy'
) a=[1
,[11,
2,3]
]; b=deepcopy(a)
print
('id(a) =',id
(a))
for i in
range(0
,len
(a))
:print(%
(i,id
(a[i]))
)print
('id(b) =',id
(b))
for i in
range(0
,len
(b))
:print(%
(i,id
(b[i]))
)print
('\ncopy'
) a=[1
,[11,
2,3]
]; b=copy(a)
print
('id(a) =',id
(a))
for i in
range(0
,len
(a))
:print(%
(i,id
(a[i]))
)print
('id(b) =',id
(b))
for i in
range(0
,len
(b))
:print(%
(i,id
(b[i]))
)
#coding=utf-8
from copy import copy, deepcopy
class
node
(object):
@classmethod
def__new__
(cls,
*args,
**kwargs)
: self =
super()
.__new__(cls)
print
('__new__ of '
, self)
return self
def__init__
(self)
:print
('__init__ of '
, self)
self.father =
none
;self.isme =
false
; self.children =
defaddchild
(self, child)
: child.father = self
return self
class
subtreenode
(node)
:def
__init__
(self,):
super()
.__init__(
) self.weight =
1if __name__ ==
"__main__"
: n = subtreenode(
).addchild(subtreenode())
n = subtreenode(
).addchild(n)
print
('\n------深拷貝只呼叫__new__方法，而不再呼叫__init__方法--------'
) n2 = deepcopy(n)
print
('\n------物件的位址資訊--------'
)print(id
(n),
id(n.children[0]
),id(n.children[0]
.children[0]
))print(id
(n2),id
(n2.children[0]
),id(n2.children[0]
.children[0]
))print
('\n------物件的屬性資訊--------'
) n.weight =
8print
(n.weight, n2.weight)
n.children[0]
.weight =
9print
(n.children[0]
.weight, n2.children[0]
.weight)
n.children[0]
.children[0]
.weight =
10print
(n.children[0]
.children[0]
.weight, n2.children[0]
.children[0]
.weight)
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