Python: Create a deep copy of a given dictionary

Last update on April 02 2025 12:32:11 (UTC/GMT +8 hours)

4. Deep Copy of Dictionary

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

Sample Solution:

Python Code:

import copy
nums_x = {"a":1, "b":2, 'cc':{"c":3}}
print("Original dictionary: ", 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 dictionary:")
nums_x["cc"]["c"] = 10
print(nums_x)
print("\nSecond dictionary (Deep copy):")
print(nums_y)

nums = {"x":1, "y":2, 'zz':{"z":3}}
nums_copy = copy.deepcopy(nums)
print("\nOriginal dictionary :")
print(nums)
print("\nDeep copy of the said list:")
print(nums_copy)
print("\nChange the value of an element of the original dictionary:")
nums["zz"]["z"] = 10
print("\nFirst dictionary:")
print(nums)
print("\nSecond dictionary (Deep copy):")
print(nums_copy)

Sample Output:

Original dictionary:  {'a': 1, 'b': 2, 'cc': {'c': 3}}

Deep copy of the said list:
{'a': 1, 'b': 2, 'cc': {'c': 3}}

Change the value of an element of the original dictionary:
{'a': 1, 'b': 2, 'cc': {'c': 10}}

Second dictionary (Deep copy):
{'a': 1, 'b': 2, 'cc': {'c': 3}}

Original dictionary :
{'x': 1, 'y': 2, 'zz': {'z': 3}}

Deep copy of the said list:
{'x': 1, 'y': 2, 'zz': {'z': 3}}

Change the value of an element of the original dictionary:

First dictionary:
{'x': 1, 'y': 2, 'zz': {'z': 10}}

Second dictionary (Deep copy):
{'x': 1, 'y': 2, 'zz': {'z': 3}}

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Python program to create a deep copy of a dictionary with nested lists using copy.deepcopy, then modify the nested list in the original and print both dictionaries to verify independence.
• Write a Python function that accepts a dictionary with nested structures, makes a deep copy using copy.deepcopy, and then compares the id() of nested objects between the original and the copy.
• Write a Python script to demonstrate the deep copy process by updating a nested value in a dictionary after performing a deep copy, ensuring that the change does not affect the copy.
• Write a Python program to convert a complex dictionary to a deep copy using copy.deepcopy and then output both the original and copied dictionaries to confirm that no shared mutable objects exist.

Python Code Editor:

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