Python: Create a deep copy of a given list

Last update on April 24 2025 12:37:01 (UTC/GMT +8 hours)

2. Deep Copy of List

Write a Python program to create a deep copy of a given list. Use copy.copy

Sample Solution:

Python Code:

import copy
nums_x = [1, [2, 3, 4]]
print("Original list: ", nums_x)
nums_y = copy.deepcopy(nums_x)
print("\nDeep copy of the said list:")
print(nums_y)
print("\nChange the value of an element of the original list:")
nums_x[1][1] = 10
print(nums_x)
print("\nCopy of the second list (Deep copy):")
print(nums_y)
nums = [[1, 2, 3], [4, 5, 6]]
deep_copy = copy.deepcopy(nums)
print("\nOriginal list:")
print(nums)
print("\nDeep copy of the said list:")
print(deep_copy)
print("\nChange the value of some elements of the original list:")
nums[0][2] = 55
nums[1][1] = 77
print("\nOriginal list:")
print(nums)
print("\nSecond list (Deep copy):")
print(deep_copy)

Sample Output:

Original list:  [1, [2, 3, 4]]

Deep copy of the said list:
[1, [2, 3, 4]]

Change the value of an element of the original list:
[1, [2, 10, 4]]

Copy of the second list (Deep copy):
[1, [2, 3, 4]]

Original list:
[[1, 2, 3], [4, 5, 6]]

Deep copy of the said list:
[[1, 2, 3], [4, 5, 6]]

Change the value of some elements of the original list:

Original list:
[[1, 2, 55], [4, 77, 6]]

Second list (Deep copy):
[[1, 2, 3], [4, 5, 6]]

Flowchart:

For more Practice: Solve these Related Problems:

Write a Python program to create a deep copy of a list containing nested lists using copy.deepcopy and show that changes in the inner lists of the original do not affect the copy.
Write a Python function that accepts a complex list (with nested dictionaries and lists), creates a deep copy using copy.deepcopy, and then prints both the original and copied lists to verify independence.
Write a Python script to demonstrate deep copying by modifying an element within a nested list after deep copy, and then compare the nested objects' id() values between the original and the copy.
Write a Python program to generate a deep copy of a list of mutable objects using copy.deepcopy, then perform modifications on the original list to confirm the copy remains unaltered.

Go to:

Previous: Write a Python program to create a shallow copy of a given list.
Next: Write a Python program to create a shallow copy of a given dictionary.

Python Code Editor:

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