Python List vs Array – when to use?

Python list vs array

Hello Techies,

In this article, we will explain Python List vs Array.

In Python, both arrays and lists are used to store data, and both data structures allow indexing, slicing, and iteration. However, there are some significant differences between these two data structures.

The main difference between the Python list and array is that the list is part of Python’s standard package, while the “NumPy package” and “array” modules must be imported for the array.

Before moving on to the differences between the Python list and array, let’s check the features and functions of lists and arrays.

What is a Python list? 

A list is a data structure that is built into Python and contains a collection of items.

The lists have several important features:

  • A list represents a group of elements.
  • Lists are sorted – The items in the list appear in a specific order. This enables us to use indexes to access any objects.
  • List are mutable, means we can modify its element.
  • The list also allows duplicate elements.
  • The list can contain any items and they can be of different types.
  • The list is dynamic which means size is not fixed.
  • A list is created by placing all the elements in square brackets [].
  • Example: data = [1, -89, “test”, “TechPlusLifeStyle”]

Lists are easily created in Python:

data = [1, -89, “test”, “TechPlusLifeStyle”]
print(data)
print(type(data))

Output is:

[1, -89, 'test', 'TechPlusLifeStyle']  
<class 'list'> 

What is a Python Array? 

In Python, an array is an object that provides a mechanism for storing multiple data items with just one identifier, making data management easier. An array is useful if you need a store set of elements of the same datatype.

The Array has several important features:

  • In Python, The size of the array is not fixed. Arrays can dynamically increase or decrease their size.
  • An array is a collection of common types of data structures that contain elements of the same data type.
  • In an array, elements can be accessed randomly using index numbers.
  • Array and list are not the same.

Where do we use arrays in Python?

  • Python arrays are used when you need to use multiple variables of the same data type. Arrays are useful when it comes to dynamically processing data.
  • If you need to store a relatively short sequence of items and have no plans to perform any mathematical operations with it, the list is the preferred choice.

Python List/Array Methods

Python has some built-in methods that we can use on lists/arrays.

Method NameDescription
append()Add an element at the end of the list
extend()Add all the elements of the list to the second list
insert()Insert an object into the defined index
remove()Removes items from the list
pop()Removes and returns an element from a given index
clear()Removes all items from the list
index()Returns the index of the first matching item
count()Calculate the number of items passed as arguments and return the count
sort()Sort the listed items in ascending order
reserve()Reverse order of items in the list
copy()Returns a shallow copy of the list

Some examples of Python List methods.

import array as arr

my_list = [4, 7, 1, 6, 7]
my_array = arr.array(i, [4, 7, 1, 6, 7])

# index() method on list
print(my_list.index(7))

# index() method on array
print(my_array.index(7))

# count() method on list
print(my_list.count(7))

# count() method on array
print(my_array.count(7))

# sort() method on list
my_list.sort()
print(my_list)

# sort() method on array
my_array.sort()
print(my_array)

# reverse() method on list
my_list.reverse()
print(my_list)

# reverse() method on array
my_array.reverse()
print(my_array)

Output is:

1
1
2
2
[1, 4, 6, 7, 7]
[1, 4, 6, 7, 7]
[7, 7, 6, 4, 1]
[7, 7, 6, 4, 1]

Python List vs Array

Here is the difference between a Python list and Array.

ListArray
There is no need to import modules explicitly to declare a ListNeed to import modules explicitly to declare a List
Cannot handle arithmetic operations directlyCan handle arithmetic operations directly
The list can store different types of elementsArray stores only the same data type of element

FAQ on Python list vs array

  1. Which is better array or list in Python?

    In Python, both arrays and lists are used to store data, and both data structures allow indexing, slicing, and iteration. An array is useful if you need a set of elements of the same datatype, the list can store a different types of elements. Arrays can handle arithmetic operations, so if you want to perform some arithmetic operations, you can use Arrays.

  2. Which is faster in Python list or array?

    Array is faster than list because it uses less memory than list.

  3. Can Python arrays hold different types?

    No, Array stores only the same data type of element.

  4. Why array is used in Python?

    Arrays are used in Python when you want to perform some arithmetic operations.

I hope you understand the difference between a Python list and an array.

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