Python Copy List

The list Copy() method will help you to make a new shallow copy of the list. The article has listed the Python Copy List.

What is the List Copy () Method in Python?

The list Copy () function will allow you to make a copy of the list in Python. It consists of two main ways to create a copy of the list, a Shallow copy and a Deep copy.

Moreover, the list copy () function will make the copy of the list and won’t affect the values in the original list. So, it will provide the freedom to manipulate the data without worrying about data loss.

What is List copy() Method Syntax in Python?

list.copy()

Parameters

• The copy method won’t take any parameters.

Returns: It will return the shallow copy of the list.

How to Create the Simple Copy of a List in Python?

In Python, it is possible to create and copy a new list with the help of the copy() function . Let us look into the example given below.

Example

# Original list
original_list = [1, 2, 3, 4, 5]

# Copying the list using slicing
copied_list = original_list[:]

# Modifying the copied list
copied_list.append(6)

# Printing both lists
print("Original List:", original_list)
print("Copied List:", copied_list)

Output

Original List: [1, 2, 3, 4, 5]
Copied List: [1, 2, 3, 4, 5, 6]

What are the other Examples of the List copy() Method?

Let us look into the examples given below of the List Copy method.

Example 1: To create the Simple List Copy

The example provided below has allowed us to create the list of Python strings with the help of the copy method which is used to copy the list to another variable.

# Creating a list of strings
original_list = ["apple", "banana", "cherry", "date"]

# Copying the list using the copy() method
copied_list = original_list.copy()

# Modifying the copied list
copied_list.append("elderberry")

# Printing both lists
print("Original List:", original_list)
print("Copied List:", copied_list)

Output

Original List: ['apple', 'banana', 'cherry', 'date']
Copied List: ['apple', 'banana', 'cherry', 'date', 'elderberry']

Example 2: To Demonstrate the working of the List copy()

The example below will illustrate how to make the Python List and then make the shallow copy with the help of the copy() function.

# Creating a Python list
original_list = [1, [2, 3], 4, [5, 6]]

# Making a shallow copy using the copy() function
copied_list = original_list.copy()

# Modifying the copied list
copied_list[1][0] = 10

# Printing both lists
print("Original List:", original_list)
print("Copied List:", copied_list)

Output

Original List: [1, [10, 3], 4, [5, 6]]
Copied List: [1, [10, 3], 4, [5, 6]]

What are Shallow Copy and Deep Copy?

The Deep copy will be referred to as the copy of the list, where it will add the element to any of the lists. So, only that list will be altered. Whereas, the Shallow copy will form the new array, but it won’t create new copies of the elements within the array. 

Example: To show the techniques of Shallow and Deep copy

The assignment operator, list copy() method, and copy.copy() method will allow us to create the list and the shallow copy.

Hence, a deep copy will be made using the deep copy() in Python. Hence, it will create changes to the original list and check if the other list is affected or not.

Example:

import copy

# Creating a list with nested lists
original_list = [1, [2, 3], 4, [5, 6]]

# Shallow copy
shallow_copied_list = copy.copy(original_list)

# Deep copy
deep_copied_list = copy.deepcopy(original_list)

# Modifying the copied lists
shallow_copied_list[1][0] = 10
deep_copied_list[1][0] = 20

# Printing all lists
print("Original List:", original_list)
print("Shallow Copied List:", shallow_copied_list)
print("Deep Copied List:", deep_copied_list)

Output

Original List: [1, [2, 3], 4, [5, 6]]
Shallow Copied List: [1, [10, 3], 4, [5, 6]]
Deep Copied List: [1, [20, 3], 4, [5, 6]]

How to Copy List Using the Slicing?

It is possible to copy the list using the list slicing method and then, we are providing the ‘a’ to the new list. Let us look into the example below:

Example

# Original list
original_list = [1, 2, 3, 4, 5]

# Copying the list using slicing
copied_list = original_list[:]

# Modifying the copied list
copied_list.append(6)

# Printing both lists
print("Original List:", original_list)
print("Copied List:", copied_list)

Output

Original List: [1, 2, 3, 4, 5]
Copied List: [1, 2, 3, 4, 5, 6]

Conclusion

To sum up, In Python, copying lists is crucial for maintaining data integrity and avoiding unintended side effects. There are several methods to copy lists, including slicing, the copy() method, shallow copying, and deep copying.

Python Copy List-FAQs