How do Shallow and Deep Copying Differ in Python?

Copying Objects in Python

Creating an independent copy of an object is a common task in programming. In Python, there are two main ways to copy an object: shallow copying and deep copying.

Shallow Copying

Python's default copying mechanism is shallow copying. This means that a new object is created with a reference to the same fields as the original object. Any changes made to the fields of the new object will also be reflected in the original object.

Deep Copying

Deep copying, on the other hand, creates a new object with separate copies of the fields from the original object. This means that any changes made to the fields of the new object will not affect the original object.

To get a fully deep independent copy of an object in Python, you can use the copy.deepcopy() function. Here's an example:

<code class="python">import copy

# Original object
obj = {
    "name": "Alice",
    "age": 20
}

# Create a shallow copy
shallow_copy = obj

# Create a deep copy
deep_copy = copy.deepcopy(obj)

# Modify the shallow copy
shallow_copy["name"] = "Bob"

# Print the original and deep copy
print(obj)  # Output: {'name': 'Bob', 'age': 20}
print(deep_copy)  # Output: {'name': 'Alice', 'age': 20}</code>

As you can see, the deep_copy retains the original values of the object, while the shallow_copy is affected by the changes made to the original object.

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