CODEWITHSUNDEEP
python
Chidananda Nayak
Chidananda Nayak

Reputation: 1201

Shallow copy operation confusion

I am trying to understand behind the code operation in shallow copy in python

created an object 

o = [1,12,32,423,42,3,23,[1,2,3,4]]

created a shallow copy and assigned to a variable 

r = copy.copy(o)

print(r)
[1, 12, 32, 423, 42, 3, 23, [1, 2, 3, 4]]

Then tried to assigning new value in two different indexes 

o[1]="ff"
o[7][1]="kk"


print(r)
[1, 12, 32, 423, 42, 3, 23, [1, 'kk', 3, 4]]

So as per shallow copy it creates reference of parent in child variable so when we change parent, it reflects in child, but here reference changed only in sublist only. Why so?

Upvotes: 0

Views: 58

Answers (1)

Dipen Dadhaniya
Dipen Dadhaniya

Reputation: 4630

Try to observe what is happening by running the below code (after the modifications):

print(id(r[1]))
print(id(o[1]))    # different

print(id(r[7]))
print(id(o[7]))    # same

print(id(r[7][1]))
print(id(o[7][1])) # same

Also, read the links that others have posted.

Upvotes: 1

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