Python: A Beginner's Guide to Data Structures and Algorithms

Joshuauche — Mon, 21 Feb 2022 22:49:39 +0000

what are Data structures
Data Structures are a remarkable way of organizing, managing and storing data in computers in such a way that we can perform operations on the saved data very efficiently.

In this article, I will briefly explain the commonly used data structures in python every programmer must know.
There are four types of built-in data structures in Python offers: list, tuple, set, and dictionary.

List
A list is well defined using square brackets which holds data that is separated by commas. A list is mutable and ordered. It can contain a mix of different data types.

# declaring an empty lists
lists = []

# initializing and defining lists with different data types
list_Numbers = [1, 2, 3, 4, 5]

# initializing and defining lists with string data types
list_string = ["Bale", "Kane", "Sterling"]

# initializing and defining lists with mixed data types
mix_list = [9, 4, "Anne"]

Now lets try to access the data stored in the list using their index numbers, which begins count from 0 i.e. the first element in the list.
open your python shell console

>>> print the first element
>>> lists = [1, 2, 3, 4, 5]
>>> print(lists[0])
1
>>>
>>> print(lists[0:3])
[1, 2, 3]
>>>
>>> # prints the last element in the list
>>> print(lists[-1])

>>> # sorting the list in ascending order
>>> lists = [2, 7, 9, 3, 1]
>>> lists.sort()
>>> print(lists)
[1, 2, 3, 7, 9]
>>> 
>>> # sorting the list in descending order
>>> lists.sort(reverse=True)
>>> print(lists)
[9, 7, 3, 2, 1]
>>>

since list are mutable, we can perform addition and deletion of element in list.
to add more elements we can use these functions: append(), extend(), and insert().
to delete elements, we can use del(), pop() and remove() function

Tuples
A tuple is a data type for storing immutable ordered sequences of elements. tuples are Immutable because you can neither add nor remove elements from tuples, or sort them in place unlike lists which are mutable.

>>> # declaring an empty tuple
>>> emptY_tuple = ()
>>> print(empty_tuple)
()

Set
Set is a mutable and unordered collection of unique elements. It can permit us to remove duplicate quickly from a list.

Dictionaries
Dictionary is a mutable and unordered data structure, used to store data. It permits storing a pair of items which are in keys and values.

>>> Dict1 = {1: 'Hello', 2: 'To', 3: 'You'}
>>> print(Dict1)
{1: 'Hello', 2: 'To', 3: 'You'}

User-Defined Data structure
stacks
A stack is a LIFO (Last In First Out — the element placed at last can be accessed at first) data structure which can be commonly found in many programming languages. This structure is named as “stack”. example of stack is in

Operations carried out on stack are push and pop.
push is used in inserting an element into the stack
pop is used in deleting an element in the stack

Queues
Queues is a also a linear data structure which uses First-In/First Out(FIFO) to store items.

Operations that can be performed on the queue are:
Enqueue - which is used to add item to the queues
Dequeue - It removes an item from the queue
Front - the front item from the queue
Rear - the last item from the queue

Binary Trees
Trees are also non-linear data structures that represent nodes connected by edges. Each Tree consists of a root node from which we can access each element of the tree.

There are other data structures which can be implemented linked list, graphs and hash tables.

Algorithms
Algorithm is a step-by-step course of action, which defines a set of instructions to be executed in a certain order to get the desired output. Algorithms are generally created independent of underlying languages

the common operations that can be done are:

Search
Sort
Insert
Delete
Update

There are three main approaches in solving an algorithm
Greedy Algorithm
Dynamic Algorithm
Divide and conquer Algorithm

References

Python 101: Ultimate Python Guide or Introduction to Modern Python

Joshuauche — Sat, 12 Feb 2022 18:44:13 +0000

What is Python?

Python is an interpreted, object-oriented, high-level programming language with dynamic semantics. Its high-level built in data structures, combined with dynamic typing and dynamic binding, make it very attractive for Rapid Application Development.

What makes python so popular?

It is simple and easy to learn syntax.
Debugging Python programs is easy
increased productivity it provides
It’s beginner friendly.
It’s open source.
It’s versatile.
Python has a large and active community
It has archive of modules and libraries

What types of jobs use Python?
Since python is a general-purpose language, it’s used across a variety of fields and industries. These are just a few job titles that may use Python:

Developer
Data analyst
Data scientist
Ethical hacker/penetration tester
Software engineer
Data journalist
Cloud architect
QA engineer

What is Python used for?

developing websites and software
task automation
data analysis
data visualization
Software testing and prototyping

Python installation steps

Visit https://www.python.org/downloads/
Select your Operating system(Windows, Linux, MacOS)
Select the release or version, click on it to download.
Double click on the file to execute and install.
For window mark “add to system paths” For more check on the python documentation for more documentations.

Let’s test our installed python

Open Terminal on Linux or cmd on windows
Run the python --version command to check if you installed the correct version. if python is installed, the output will be similar to as below:

C:\Users\UCHE>python --version
Python 3.9.7

C:\Users\UCHE>

we can now open python interpreter shell on the terminal with this command. the output will be similar to as below:

C:\Users\UCHE>python
Python 3.9.7 (tags/v3.9.7:1016ef3, Aug 30 2021, 20:19:38) [MSC v.1929 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>>

Our first code is to print hello world using python.

>>> print("Hello, World!")
Hello, World!
>>>

Next, lets read from user input, declare it in a variable and print

>>> name = input("enter your name: ")
enter your name: Bale
>>> print("hello, " + name)
hello, Bale
>>>

we can also use a code editor and IDEs(Integrated Development Environment) to write our python code.
Here are the list of best python IDEs and code editors

DEV Community: Joshuauche

Python: A Beginner's Guide to Data Structures and Algorithms

Python 101: Ultimate Python Guide or Introduction to Modern Python

References