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Create copies of objects in Python using the `copy` module to work with data without altering the original.

# Python Copy Usage

In Python, the `copy` module provides functions for creating shallow and deep copies of objects. This can be useful when you want to work with copies of objects without altering the original data. In this guide, we will explore how to use the `copy` module in Python.

## Shallow Copy

A shallow copy creates a new object but does not create copies of nested objects within the original object. This means that changes made to nested objects in the copy will affect the original object. To create a shallow copy of an object, you can use the `copy` module’s `copy()` function.

“`python
import copy

original_list = [1, 2, [3, 4]]
shallow_copy_list = copy.copy(original_list)

original_list[2][0] = 5

print(original_list) # Output: [1, 2, [5, 4]]
print(shallow_copy_list) # Output: [1, 2, [5, 4]]
“`

As you can see in the example above, changing the nested list in the original list also affects the shallow copy of the list.

## Deep Copy

A deep copy creates a new object and recursively creates copies of all nested objects within the original object. This means that changes made to nested objects in the copy will not affect the original object. To create a deep copy of an object, you can use the `copy` module’s `deepcopy()` function.

“`python
import copy

original_list = [1, 2, [3, 4]]
deep_copy_list = copy.deepcopy(original_list)

original_list[2][0] = 5

print(original_list) # Output: [1, 2, [5, 4]]
print(deep_copy_list) # Output: [1, 2, [3, 4]]
“`

In this example, changing the nested list in the original list does not affect the deep copy of the list.

## Copying Custom Objects

You can also use the `copy` module to create copies of custom objects. When working with custom objects, it is important to implement the `__copy__()` and `__deepcopy__()` methods to define how the object should be copied.

“`python
import copy

class Person:
def __init__(self, name, age):
self.name = name
self.age = age

def __copy__(self):
return Person(self.name, self.age)

def __deepcopy__(self, memo):
return Person(copy.deepcopy(self.name, memo), copy.deepcopy(self.age, memo))

# Create a custom object
person1 = Person(“Alice”, 30)

# Create shallow and deep copies of the object
shallow_copy_person = copy.copy(person1)
deep_copy_person = copy.deepcopy(person1)

print(person1.name, person1.age) # Output: Alice 30
print(shallow_copy_person.name, shallow_copy_person.age) # Output: Alice 30
print(deep_copy_person.name, deep_copy_person.age) # Output: Alice 30
“`

When working with custom objects, make sure to implement the necessary methods to ensure that the object is copied correctly.

## Conclusion

The `copy` module in Python provides a convenient way to create shallow and deep copies of objects. By understanding how to use these functions, you can work with copies of objects without altering the original data. Remember to use shallow copies when you only need a top-level copy of an object and deep copies when you need copies of all nested objects within the original object.