Contents
This quick tutorial will show you how to copy a list in Python using the built-in copy function as well as the list slicing method.
Checkout this video:
Introduction
Python lists are mutable i.e. they can be changed. Copying a list means creating a new list with the same elements as the original. You can do this in several ways:
-The easiest way is to use the built-in method list.copy(). This creates a shallow copy of the list i.e. if the original list contains any mutable objects (like lists or dictionaries), they are also copied but not duplicated i.e. both the original and the copy refer to the same object.
-You can also use the method list() on any iterable to create a new list e.g. you can use it on a string to create a list of characters. This is called conversion and produces a deep copy of the original i.e. all mutable elements are duplicated, not just referenced.
-If you want to duplicate only part of a list, you can use slicing e.g.:
new_list = old_list[start:end]. This creates a shallow copy of the specified elements (start and end are indices).
What is Python?
Python is a versatile language that you can use on the backend, frontend, or full stack of a web application. Python is a high-level, interpreted, and general-purpose programming language with an elegant syntax that is easy to read and write.
What is a list?
In Python, a list is an ordered collection of objects. You can create a list by enclosing an comma-separated sequence of objects in square brackets ([ ]). Lists are mutable, which means you can change their content without changing their identity.
How to copy a list in Python?
There are a few ways to copy a list in Python. The most common way is to use the built-in method list.copy(). You can also use the + operator to concatenate two lists, or the slice operator to make a shallow copy.
Why do we need to copy a list?
There are a number of reasons you might want to make a copy of a list in Python. Maybe you need to make a modification to one list, but you want to keep the original intact. Or, perhaps you want to break up a list into smaller chunks for processing. Regardless of your reason, it’s important to know how to copy a list in Python.
There are two ways to make a copy of a list in Python. The first is to use the built-in method list.copy(). This method returns an exact copy of the original list, including any nested lists. The second way to copy a list is by using the built-in method list() with the original list as an argument. This method also returns an exact copy of the original list, but it doesn’t handle nested lists as well as list.copy().
To learn more about copying lists in Python, check out our detailed tutorial: https://dbader.org/blog/how-to-copy-a-list-in-python
What are the different methods to copy a list in Python?
There are a few different ways to copy a list in Python. One way is to use the built-in method list.copy(). This method will create a new list with the same elements as the original list.
Another way to copy a list is to use the built-in method slice(). This method will create a new list with the same elements as the original list, but it will not include any of the elements from the start index to the end index.
The last way to copy a list is to use the built-in method extend(). This method will add all of the elements from one list to another.
Here are some examples of how to copy a list using each of these methods:
List.copy():
“`python
>>> my_list = [1, 2, 3]
>>> new_list = my_list.copy()
>>> new_list
[1, 2, 3]
“`
Which method is the best to copy a list in Python?
There are a number of ways to copy a list in Python, and the best method to use depends on the situation. If you just want to make a shallow copy of a list (meaning that the copy and the original will share references to the same objects), then you can use the built-in list.copy() method. If you want to make a deep copy of a list (meaning that the copy and the original will not share references to any objects), then you can use the built-in copy.deepcopy() method. Finally, if you need to make a custom version of a list (for example, if you want to remove certain elements from the list), then you can create your own copy function.
What are the benefits of copying a list in Python?
There are many benefits to copying a list in Python. Firstly, it can help you avoid mutating your original data. Secondly, if you need to make changes to a list, you can do so without affecting the original data. Lastly, it can also help you improve the performance of your code by avoiding costly operations such as recreating lists.
How can we use the copied list?
There are a number of ways to copy a list in Python. The most common way is to use the built-in list method .copy(). This will create a new list with the same elements as the original.
Another way to copy a list is to use the built-in method list.extend(). This method will add all the elements of the original list to the end of the new list.
You can also copy a list by using the slice operator [:]. This will create a new list with all the elements of the original.
Once you have created a copy of a list, you can use it for any purpose you like. You can add or remove elements, sort it, reverse it, or use it for any other operation that you would use a normal list for.
Conclusion
In this article, we have seen how to copy a list in Python. We have also seen different ways of copying lists, and the performance implications of each method.
