WHAT IS LIST IN PYTHON 2023

WHAT IS LIST IN PYTHON In python, a list is a type of array or container where you can store different types of data. The elements stored in the list are sorted and indexed in a certain order, and indexing is done with 0.

A list can be created by enclosing elements in square bracket WHAT IS LIST IN PYTHON:

It is a mutable, heterogeneous, and sequential data structure in python that supports efficient insertion, addition, deletion, and concatenation.

which can perform the operations append(x), extend(iterable), insert(i, x), remove(x), pop([i]), clear(), etc.

Unlike variables, identical lists do not share the same memory address. The following examples illustrate the same.

List of understandingsWHAT IS LIST IN PYTHON :

List Comprehension provides a short and elegant way to create a list.

This is the basic syntax:

List=[loop_condition expression] WHAT IS LIST IN PYTHON 2023

 

List Limits WHAT IS LIST IN PYTHON:

In python, lists are efficient data structures, and understanding lists also makes them easier to construct and manipulate. However, there are some limitations of lists, for example, they do not support vectorized operations such as addition of elements, dot product, cross product, etc WHAT IS LIST IN PYTHON 2023.

The numpy array module is used to perform such operations which are more efficient and convenie

WHAT IS LIST IN PYTHON The most basic data structure in Python is a sequence. Each element of the sequence is assigned a number – its position or index. The first index is zero, the second index is one, and so on.

Python has six built-in sequence types, but the most common are lists and tuples, which we’ll see in this tutorial WHAT IS LIST IN PYTHON 2023.

There are certain things you can do with all types of sequences. These operations include indexing, division, addition, multiplication, and membership checking. In addition, Python has built-in functions to find the length of a sequence and to find its largest and smallest elements WHAT IS LIST IN PYTHON 2023.

Python lists
A list is the most versatile data type available in Python, which can be written as a comma-separated list of values ​​(items) enclosed in square brackets. The important thing about a list is that the items in the list don’t have to be of the same typeWHAT IS LIST IN PYTHON 2023.

Creating a list is as simple as putting different comma-separated values ​​in square brackets. For example –

Like string indexes, list indexes start at 0, and lists can be sliced, concatenated, and so on.

Accessing values ​​in lists WHAT IS LIST IN PYTHON 2023 To access values ​​in lists, use square brackets to split along with the index or indices to get the value available at that index. For example –

You can update one or more list elements by placing a slice on the left side of the assignment operator, and you can add elements to the list using the append() method. For example WHAT IS LIST IN PYTHON 2023 –

print list[2]
Note − the append() method is discussed in the following section.

After executing the above code it will produce the following result −

Value available at index 2:
1997
New value available at index 2 WHAT IS LIST IN PYTHON WHAT IS LIST IN PYTHON 2023:
2001
Remove list elements
To remove a list element, you can use either the del command if you know exactly which element(s) you are removing, or the remove() method if you don’t. For example –

[‘physics’, ‘chemistry’, 1997, 2000]
After deleting the value at index 2:
[‘physics’, ‘chemistry’, 2000]
Note − the remove() method is discussed in the following section WHAT IS LIST IN PYTHON 2023.

Basic list operations WHAT IS LIST IN PYTHON
Lists respond to the + and * operators similarly to strings; also mean concatenation and iteration here, except that the result is a new list, not a string.

Lists actually correspond to all the general sequential operations we used with strings in the previous chapter.

In this Python List tutorial, we’ll explore ways to create, access, cut, add/remove elements to Python lists, which are probably one of the most useful data types WHAT IS LIST IN PYTHON 2023

Python has 4 collection data types as shown below WHAT IS LIST IN PYTHON 2023:

List
File
Dictionary
Dull
In this tutorial, we will discuss List and its various operations in detail. In Python, a list is a data structure or it is like an array that is used to store multiple data at once.

=> Explore Python training series here

If you have experience with other programming languages ​​like Java, C, C++ etc. then you will be familiar with the concept of arrays. A list is almost the same as an array WHAT IS LIST IN PYTHON 2023.

What you will learn: [hide]

What are Python lists
Python list characteristics
Python lists are sequences of containers
Python lists are ordered sequences
Python lists are mutable sequences
Manipulating Python lists
Creating a list WHAT IS LIST IN PYTHON
Adding items to a list
Access items from a list
Make a shallow copy of the list
Reverse the list
Removing items from a list
Exchange items from a list
FAQs WHAT IS LIST IN PYTHON
More about lists in Python
What is a data structure?
What is a list?
Creating a list
Access the values ​​in the list
Negative indexing
Cutting the list
Adding elements to a list
list append() vs extend()
Delete or remove elements from a list
List of methods
Conclusion
Recommended reading
Python lists WHAT IS LIST IN PYTHON 2023.

What are Python lists

In Python, a list is a data type that stores a collection of different objects (items) in square brackets ([]). Each item in the list is separated by a comma (,) with the first item at index 0.

Note: Unless otherwise noted, all examples in this tutorial will run directly from the Python environment.

In the above example, we can see that the list contains String objects as items and each item is separated by a comma WHAT IS LIST IN PYTHON.

Python list characteristics
Before we look at how we can manipulate the items in a list, let’s look at some of the features that make lists popular in Python WHAT IS LIST IN PYTHON 2023.

Python lists are sequences of containers
Unlike flat sequences (string, array.array, memoryview, etc.) that can only contain items of one type, a list is a container sequence that can contain items of one type as well as multiple types.

Example with items of one type WHAT IS LIST IN PYTHON

Let’s open our python shell and define a list of numbers WHAT IS LIST IN PYTHON 2023.

>>> numbers = [‘one’,’two’,’three’,’four’,’five’]
>>> numbers
[‘one two three four five’]
The above example shows a list of items of the same type, in this case of type string(str).

Example with items of different types

Let’s open our Python shell and define another version of the list of numbers.The above example shows a list of items of different types. The types are string, integer and float.

// a sketch showing a list of items and their types as annotations
A Python list can also contain all objects such as functions, classes, modules, lists, tuples and much more.

Open the editor and paste the code below:

# create a list containing all the different data types defined above, including boolean.
my_list = [test, instance, colors, False]
print(my_list)
Exit WHAT IS LIST IN PYTHON

Python lists are sequences of containers

Python lists are ordered sequences
A Python list is an ordered collection of objects. The position of each item in the list is very important. In fact, two lists with the same items are not the same if the order in which the items are placed is not the same.

This property of a Python list allows its items to be accessed by index and division (more on that later).

Python lists are mutable sequences
Python lists are mutable. But what is a mutable object? It is simply an object that can be modified after creation. Examples of other mutable sequences are dictionary, array.array, collections.deque.

Why changeable? Sequences like lists are used for complex operations, so it makes sense that they should be able to change, grow, shrink, update, etc. This is only possible with mutability. Mutability also allows us to edit lists in place (more on that).

 

Python lists are mutable sequencesWHAT IS LIST IN PYTHON 2023

From the above output, we notice that the list before and after the modification is different. However, the Id value is the same. The Id value here represents the address of the object in memory – this is obtained using Python’s id().

This tells us that even though the contents of the list have changed, it is still the same object. So this fits our definition: “It’s simply an object that can be modified after it’s created”

Note: In the example above, we used indexing (more on that) to modify the list.

Manipulating Python lists WHAT IS LIST IN PYTHON 2023.

With lists in Python, the sky is our limit. We can do countless things with lists like adding, deleting, indexing, splitting, checking membership and much more. Python also has built-in features that make manipulating lists exciting.

In this section, we look at some commonly used list operations.

Creating a list
To create a list, simply enclose multiple items or expressions in square brackets separated by commas.

Python list() can take sequence types and convert them to lists. This is the typical way to convert a tuple to a list.

Lists are used to store multiple items in a single variable WHAT IS LIST IN PYTHON 2023.

Lists are one of the 4 built-in data types in Python used to store collections of data, the other 3 being Tuple, Set and Dictionary, all with different qualities and uses.

List items are indexed, first item has index [0], second item has index [1], etc.

Ordered
When we say that lists are sorted, it means that the items have a defined order and that order will not change.

If you add new items to the list, they will be placed at the bottom of the list.

Note: There are some list methods that change the order, but the general rule is: the order of the items is not changed.

ChangeableWHAT IS LIST IN PYTHON 2023.
A list is mutable, which means we can change, add, and remove items in the list after it has been created.

Allow duplicates
Because lists are indexed, lists can have items with the same value WHAT IS LIST IN PYTHON:

It is also possible to use the list() constructor when creating a new list WHAT IS LIST IN PYTHON.

Example
Using the list() constructor to create a list WHAT IS LIST IN PYTHON 2023:

thislist = list((“apple”, “banana”, “cherry”)) # note the double parentheses
print (this list)
Python collections (arrays)
There are four types of collection data in the Python programming language:

A list is a collection that is ordered and mutable. Allows duplicate members.
A tuple is a collection that is ordered and immutable. Allows duplicate members.
A set is a collection that is unordered, immutable*, and unindexed. No duplicate members.
A dictionary is a collection that is organized** and mutable. No duplicate members.
*Set items are immutable, but you can remove and/or add them at any time.

**As of Python 3.7, dictionaries are sorted. In Python 3.6 and earlier, dictionaries are unordered.

When choosing a collection type, it is helpful to understand the properties of that type. Choosing the right type for a particular data set could mean preserving meaning and could mean increasing efficiency or security.

Lists and tuples are probably Python’s most versatile and useful data types. You can find them in virtually every non-trivial Python program.

Here’s what you’ll learn in this tutorial: You’ll cover important properties of lists and tuples. You will learn how to define them and how to manipulate them. When you’re done, you should have a good feel for when and how to use these types of objects in Python WHAT IS LIST IN PYTHON.

Take a Quiz: Test your knowledge with our interactive “Python Lists and ntices” quiz. Upon completion, you will receive a score to track your learning progress over time:

Python lists WHAT IS LIST IN PYTHON
In short, a list is a collection of arbitrary objects, somewhat similar to an array in many other programming languages, but more flexible. Lists are defined in Python by enclosing a sequence of comma-separated objects in square brackets ([]) as shown below:

Important properties of Python lists are as follows:

Lists are sorted.
Lists can contain any objects.
List elements are accessed by index.
Lists can be nested to any depth.
Lists are variable.
Lists are dynamic.
Each of these features is explored in more detail below WHAT IS LIST IN PYTHON 2023.

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Lists are sorted
A list is not just a collection of objects. It is an ordered collection of items. The order in which you specify the elements when defining a list is an inherent characteristic of that list and is maintained throughout the list’s lifetime. (You’ll see the unordered Python data type in the next tutorial on dictionaries.)

Lists that have the same elements in a different order are not equal:

In topics of protection, as in subjects of faith – all people chooses for himself the most that he WHILE LOOP IN PYTHON.

 

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