In this tutorial, we’ll learn what python sequences are? How do they interact with python and how we can use sequences in python?
Sequences are one of the most core topics in any programming language specifically in python because python allows itself to be more readable. Sequences play an important role in writing code that’s easily readable.
So let’s take a look at what sequences are and how we can use them in python.
So sequences in python are a collection of elements, we will learn all about this and try to understand what can you do with those sequences? Then we will look at what are the operations that we can perform on sequences.
We’ll also take a look at the types of python sequences, sequence operations, and sequence functions. What are the uses of them and how we can use them? We will cover all details in this tutorial.
let’s get started.
What are Sequences in Python?
A sequence is a generic term used to define a collection of elements in which order is important.
So a sequence is basically just a term that is assigned to refer to a collection of elements in which order is important to order. Meaning if something is added first and then something else is added after it, the order in which these two things were added is preserved.
So if you would be asking from that sequence, give me the first item. So it won’t randomly select any item. It will give you the item that was added right at the beginning.
Now again there are other operations and functions that you can perform on it as well. Which we’ll take a look at but still you need to remember the order is very important.
It is also to be noticed that this collection of elements are not homogeneous. This basically means that you can have a collection of elements where each element is of a different type.
You can store a number, you can store an object, you can store a string then you can store some other object, you can store a float number, which is a fractional number and you could store many different kinds of things there as well.
So it’s not necessarily the case that you need to store just one particular kind of data in all the sequences. So you can use that to your advantage and just make sure that you understand that order is important here.
The order in which the sequences are added and removed items are added and removed in sequences is really important.
Types of Python Sequences
There are mainly six types of sequences in python that we need to know. Some of the types that have mostly been used, and others are not that well used and they have very niche and particular use cases. We will discuss more in detail below with examples.
So the following are the main types of python sepeuences:
Let’s discuss each type of sequence in detail with examples.
The list is the most versatile sequence type and you can create it using the
 brackets. The list is one of the basic data types in python they are used to store a collection of data and they maintain the order in which each item that is added is added at a particular index and when they are removed the indexes are re-indexed.
So if I remove something from the middle then everything after that gets re-indexed which will be shifted one position ahead of its original position.
The list sequence is mutable. Mutability basically means that you can manipulate the data inside the list, you can add new items, remove old items, you can remove items from particular indexes, you can get a slice of the index you can do a lot of things.
Tuples are basically the same as lists but the difference that they have from lists is that tuples are immutable and you need to use
() parenthesis to create them. You cannot do anything with a tuple after defining it. You cannot modify it and add data to it neither can you remove data from it.
The benefit of a tuple is that if you want to provide some constant collection of data that you know is not going to change and also is not supposed to change so you just declare a tuple add the values in it. After that, you cannot modify it, if you will try to modify it will throw an error.
The range() object is a built-in python function and they are very often used when we want to loop over certain things. A range is basically a sequence of numbers that we defined. So we tell python that I want a range of numbers ranging from 0 to 100.
The range() function gives you numbers in a particular sequence. So they hold a collection and give you the numbers. It will generate the sequence of integers with the start and end range is given.
You can also create a list or tuple or any other kind of collection using the range() function object. Check full article about range() function here.
Strings are just a collection of characters that are added one after the other and you can write in the single-quotes (”) or double-quotes (“”).
Python strings are also immutable, you can only reassign the new string to the variable but can’t make any changes in the string.
Let’s say if you have a particular word ‘c a t’ cat then you can’t jumble up the words and still have it mean the same thing that’s not going to be possible because there could be multiple mutations and permutations and combinations possible for that. So each particular sequence has a particular meaning.
bytes() function is the core built-in type for manipulating the binary data. Bytes objects are immutable sequences that are mean you cannot modify them.
The syntax of bytes is the same as string type but it will return the bytes sequence with a prefix of
bytearray() function is also a core built-in type. bytearray objects are mutable and you can modify them. You can add a new element, you can remove the old element from the byte array objects.
Python Sequence Operations
The python operations that you can execute on a sequence. A sequence as we have already discussed is just a term that is defined to describe things that have a collection of elements.
There are four main operations for any sequence and these operations you can implement on the sequence to check the specific element is exist or not, you can slice the element, you can concatenate the element, etc.
The following are the main operations:
Membership operation implements when we want to check that the specific element exists or is not in the sequence. For this, we used the (in) and (not in) operators.
Concatenation operation means when you want to add two things and make something new. This is what actually concatenation means is that you have one sequence and you have another sequence and you want to concatenate one sequence after the other sequence.
So, we will use the (+) operator to concatenate two sequences. It will add the second sequence’s elements to the first sequence.
This Repeat operation we used when we need to print the same sequence of n times. So it will loop through the same sequence’s elements for printing for the n number of times that we will be given.
So, we will use the (*) operator to repeat sequences over and over again. It will print the same sequence’s elements for the n times.
The slicing operator allows us to just slice off a particular element or a particular group of elements. It will cut off the elements from the sequence based on your given order to start and end. The order always starts from 0, remember this.
Python Sequence Functions
The python sequence functions are used to perform any action on sequence to modify or get some details. Like, if you want to count the elements of the sequence, want to get min, max from the sequence, and insert, delete, clear, etc, and more.
Let’s have a look at some sequence functions.
append() function is used to add an item to the end of the sequence.
len() function is used to get the total length of the sequence, which means how many elements are in the sequence. It is also the same if you use
count() to get the total element of the sequence.
insert() function is used to insert an item in the sequence at a specified position. The first parameter of this function is an index of an element and the second parameter is an element that you want to insert.
remove() function is used to remove a specific item from the sequence. It will throw an error if that value does not exist in the sequence.
pop() function is used to remove the item from the specific position of the sequence. If the position index is not defined then it will remove the last item of the sequence.
index() function is used to get the index of an item of the sequence. It will return the index of the first occurrence.
It allows three-parameter, first is the item to get index, second and third is the start and end point as slice notation, so it will search on that particular subsequence. These start and end parameters are optional.
reverse() function will reverse the place of elements of the sequence.
copy() function is used to make another copy of the sequence. When you want to make another sequence with the same elements then use the copy() function to create it.
max() and min() function
min() are used to get the higher and lower value from the sequence. When you want to get the maximum value from the sequence then use the max() function and if you want to get the minimum value then use the min() function.
Hope you understand the all guides on python sequences, types, operations, and functions. If you still have any queries please let me know in the comment section I’ll respond to you ASAP.