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The Ultimate Python Tutorial For Beginners Covering All The Basic Topics, From Variables To Classes & Objects

Tyagiquamar — Sun, 26 Mar 2023 16:14:28 +0000

Programming is basically designing and building an executable computer program that is used to accomplish a specific computing task to generate some results. For example, we design a calculator that can be used to perform different arithmetic operations. The need for programming occurs when we try to communicate and instruct the computer to do some tasks we want but the problem is computer only understands the binary language. Programming languages do the work for us by converting the high-level language to binary. One of the best and easy to work with programming language is python.

Python is an interpreted, high-level, and general-purpose programming language. It is created by Guido van Rossum and was first released in 1991. It is very easy to understand, from a beginner's perspective python is the best choice to start. It uses an interpreter to convert the high-level language into a low-level language. It has become famous because of its one-liners, Vast amount of packages, and active community of developers.

Python provides lots of advantages for its developers, below is a list containing some of them.

Advantages
Versatile Language Can be used for different purposes.
Open Source with an Active Community of developers.
Has All the Libraries You Can Imagine.
Large and distinct amount of modules.
Easy to learn and extend.
Object-oriented with simple syntax.
Well, You have seen the advantages of python but still wondering why should you learn it. below are some reasons which can justify it.

Why One Should Learn Python?
High salary Job Offers.
Data Scientists First Love.
can do scripting & automation.
Make Data Preprocessing easy.
Supports Testing.
Used for Web Development.
It is simple & easy to learn.
Have a massive community of people.
High In Demand.
Now, That You Have Understood What and Why We Need Python. It's The Right Time To Go Forward and Start With Its Basics.

--------------TABLE OF CONTENTS---------------

How Does Python Works??
Variables
Operators ▶ Types of Operator
Comments ▶ Single Line Comment ▶ Multiline Comment
Taking Input and Printing Output
Data Types ▶ Numbers ▶ Strings ▶ List ▶ Tuples ▶ Set ▶ Dictionaries
Indexing & Slicing
Type Conversion
Conditionals 10.Loops ▶ for ▶▶ range ▶▶ enumerate ▶ while
Functions ▶ Recursions ▶ Lambda
Package ▶ pip
random module
Files and Their Operations
Class & Object
What's Next
How Does Python Works?? Python is an interpreted language, which means it uses an interpreter to convert the Human Understandable Code into Machine Understandable Code.

The Best Advantage of using an interpreted language is that they are platform-independent. Unlike C++/C Where You have to Compile the Code, and after a successful compilation a new file gets created that contains the Machine Code that is understood by the CPU. In Python, Instead of translating the code into Machine Code, The Code is translated into bytecode.

Byte Code Is a low-level set of instructions that can be executed by an interpreter. It is executed on virtual memory.

The Source Code of Python is compiled into byte code, and then with the help of Python Virtual Memory, it is again converted into the machine code that the computer can understand.

Variables In python, a variable is the name of a memory location that is assigned with some value. For Example:- a = 5, where a is the name of the variable that is assigned with the value 5. You can refer to a variable as a container that can store any value.

Variable Operator Value
a = 20

b = 60
c = 'Ram'

Operators Operators are a set of symbols that are used to define a computation task between variables. Ex:- a+b, here + is an operator, that adds values of a & b c / d, here / is an operator, that divides c from d

There are 7 types of operators available in python —

Arithmetic operators * + / ** % -
Assignment operators = += =+ -= -= !=
Comparison operators < > !< !> =< >= ==
Bitwise operators & ^ ~ << >>
Identity operators is ,is not
Logical operators and or not
Membership operators in ,not in

Comments Comments are part of source code that is ignored by the compiler. They are mostly used to explain the code to others. Comments make your code more readable.

There are two types of comments, Single Line and Multiline. In python, you can write comments with the help of # and ''' '''

Single Line Comment

Another Single Line Comment

''' Single Line Comment '''

An

Example of

Multiline Comment Using '#'

''' An
Example of
Multiline Comment '''

Taking Input and Printing Output Input allows a user to insert a value into a program and output allows users to retrieve values back from the program. To Take Inputs from the user we use input() function. To Show the Output we user print() statement.

a = 5
b = int(input("Enter a Number:-"))
sum = a+b

print(sum)

Enter a Number:- 10
15

Data Types
a data type is an attribute of data that explains the computer how the developers intended to use the data. In simple words, data type explains the type of value a variable has. There are mainly 6 types of data types in python.
Numbers
It is one of the basic and most used data types in python. Integers, Floats, and Complex Numbers fall under the category of numbers. To check the type of variable you can use type()
```
                         OUTPUT
```
a = 10
print(type(a))
b = 4.5
print(type(b))
c = 1+6j
print(type(c))
Strings
A Sequence of Unicode Characters is called a string. To Define a string in python we use a single or double quote end with the same.

a = 'R' OUTPUT
print(type(a))
b = 'Python Programming'
print(type(b))

List The list is an ordered sequence of items. They are mutable, which means you can delete and update any element from the list. It can store multiple items from different data types at a time. To Defined a list we use [ ]

data = [98, 'Karl', 85.6,98] OUTPUT
print(type(data))

Tuple A Tuple is similar to a list the only difference is they are immutable, which means you can’t change any element from a tuple. They are very important in scenarios where your data is important and you don’t want to update it. To Defined a tuple we use ( )

data = (9,'Kat',79.89,9) OUTPUT
print(type(data))

Set It is an unordered sequence of items. It doesn’t have any repeated values, unlike lists and tuples. There are many operations that you can perform through sets like union, intersection, etc. Set Object is not subscribable. To Define a set we use { }

data = {9,10,11} OUTPUT
print(type(data))

Dictionary It is an unordered collection of keys and values. Dictionaries are mostly used to store large amounts of data. To Defined a Dictionary we use {KEY:VALUE}

dictt1 = {'id' : 'RF5701', 'name' : 'Karl', 'batch':879}
dictt2 = {
'id' : ['RF5701','RF5702'],
'name' : ['Karl', 'Kat'],
'batch' : [879,880]
}
print(dictt2.keys()) ### Prints all the keys in a list
print(dictt2.values()) ### Prints all the values

Indexing and Slicing Indexing is the process of fetching a value of a given index. There are two types of indexing- Positive and Negative. Positive indexing starts from the 0th index and Negative indexing starts from the last index.

Slicing is the process of retrieving values from a given range. The Syntax from slicing is [BottomIndex:TopIndex:Step] , here the bottom index is the lower index value and TopIndex is the higher index value and Step represents how many items it Jump or skips each time. At Default The Step is 0. The top index value is always dropped which retrieving values.

Let’s understand each one —

data = [1,2,3,4,5,6,7,8,9]

''' Indexing ''' OUTPUT RESULT
print(data[0]) 1 Fetch The Value at index 0
print(data[-1]) 9 Fetch the value at last index
print(data[-3]) 7 Fetch the value at last third index

''' Slicing '''
print(data[0:1]) 1 Value of 0th index
print(data[1:4]) [2,3] Values from 1st index to 3rd index
print(data[0:8:2]) [0,2,4,6] Values from 0th index to 7th index _ with a Jump of 2
print(data[0:-2:2]) [0,2,4,6] "" (Negative Indexing)

Type Conversion
It is the process of converting a data structure into another.
```
             CODE        OUTPUT
```
a = 2 type(a)
b = float(2) type(b)

c = str(b) type(c)
d = list(c) type(d)

Conditionals Conditional helps us to perform some computation tasks based on some given condition. in python, we have if statements to perform conditional tasks.

if condition:

task
else:
task
----------Example-------------
if rain:
Stay
else:
Go
--------Combining Multiple if--------
if rain and thunder:
Stay:
elif rain:
Go With Umbrella
else:
Go

Loops
Loops Are Used to perform a certain task multiple times. They provide code reusability. With Loops, a Small Chunk of Code Can Perform Big Tasks.
There are two types of loops in python:-
For Loop
a For Loop Iterates over something on a given range. to define a for loop we use for keyword. Syntax:-

for attribute in range(lower_range, upper_range):

Task

for i in range(0,10):
print(i) ## Prints Numbers from 0 to 9
range(): It returns a sequence of numbers based on the range given. It starts with the lower range and then increments it every time by one until the top range is met. The Top Range Values Always got dropped.

range function is good when you need vales but what should you do if you need both values and index ??

Enumerate(): It is used to iterate over an element and return index and value of each index.

lst = [1,2,3,4,5]
for index, value in enumerate(lst):
print("At Index", index, "The Value is ",value)
''' The Above Code Will Return The Index and Value At Each Index of the list
OUTPUT will be
At Index 0 The Value is 1
At Index 1 The Value is 2
At Index 2 The Value is 3
At Index 3 The Value is 4
At Index 4 The Value is 5
'''

While Loop It iterates over something until the condition is true or false.

while True:

Task

i = 0
while i<10:
i = i+1 ## The Loop Will Run Until i value becomes equals to
10, Means it will run 10 times.

Functions It is a block of code that only executes when called. You Can Pass, Put and receive data from a function. Functions make source code more structural and readable. They Provide Code reusability and Abstraction.

There are two parts of functions — Function Definition, Where the function body lies and Function Calling Through which the function is called.

To create a function we use def keyword.

def function_name(attributes): ## Parameters
task

function_name(attributes) ## Arguments

def add(x,y):
sum = x+y
print(add(6,9))
'''OUTPUT
15
'''
Recursive Function
It is a kind of function that calls itself recursively. In a recursive function, there are at least two calling statements. One inside the function and the other outside the function.

def function():
------
------
function() ## Inside the function calling

function() ## Calling (At Start)

----Program To Check Palindrome Using Recursion in Python------
def ispalindrome(word):
if word[0] != word[-1]: return False
if len(word) < 2: return True
return ispalindrome(word[1:-1])

print(ispalindrome('152'))
Lambda Function
Lambda Function is a function that is defined with a name. It is also named an anonymous function. It has no body and doesn’t require def keyword for definition. It can take up to any number of arguments but only one expression.

''' Program To Check Whether a Number is Even or not '''
even_or_not = lambda num : num%2-==0

print(even_or_not(5))

False

Package A Package in python is a collection of modules and functions that are put together to perform a certain task. It is basically a directory with python files and a file named init.py that means every directory inside the python path with file init.pyconsidered as a python package. You Can Create your own package or use the inbuilt packages. Python also offers you the ability to use packages created by other developers.

PIP is a package management system that is used to install and manage external libraries in python.

pip install PACKAGE_NAME

pip install pandas

random module it is an inbuilt module in python that is mainly used to generate random numbers within a range. It provides many different functions that provide randomness to your source code. Like any other module or library To Use it you first have to import it. import random

------ Some of the most used random module functions ------
import random
''' Generate a random integer between the given range '''
print(random.randint(1,10)) ## 3
print(random.randrange(1,10,5)) ## 15 (With Step)
''' Generate a random number between 0 and 1 '''
print(random.random())
''' Save the state of random number ''
random.seed(100)
''' Select a random choice '''

random.choice(DATATYPE)

print(random.choice([1,2,3,4,5])) ## 4

Files & Operations A file is a collection of data stored in one unit or location. in general, we divided files into two parts — text and binary files. Text files are simple files that you own and Binary Files Contains data that is only readable by computers. In python to open a file we have open() and to close files we have close()

There are different modes in which you can open a file Like Write(w), Read (r), Append (a), etc.

--------- Reading a File --------
open("FILEPATH/FILENAME.txt")
--------- Reading a File in append Mode --------
open("FILEPATH/FILENAME.txt","a")

--------- Opening a File With Handling Exceptions --------
try:
f = open("FILEPATH/FILENAME.txt", "a")
#### Some Tasks
finally:
f.close()
--------- The Best Way To Open and Close File ------
with open("FILEPATH/FILENAME.txt", "a", encoding='utf-8') as f:
-------
-------
Some Task
--------
f.close()

Class & Object Class & Object both are key parts of Object-Oriented Programming. A Class Works as a blueprint for an object whether an object is an instance of the class. For example, if you consider Employee as a class then Different Employees With Salary, Age, Experience, Department are objects.

A Class Is similar to a function the difference is that to create a class you will use class keyword.

class Data:
-----
-----
You Can Create a Function Inside the class too. a Function that is defined inside a class called a module. Also, variables inside the class are called class attributes.

class Data:
name = 'Ram'

  def __init__(self,age,salary):             ##Constructor
       self.age  = age
       self.salary = salary
  def show(self):
     print(self.age)
     print(self.salary)

init is a reserved method for classes in python that works as a constructor. This method is automatically called when the source code executes. It is mostly used to initialize variables inside the class.

Objects Are the instance of the class. With the help of an object, you can access both attributes and methods of the class. To create an object for the class you need to follow the syntax : Object_name = Class_name(values)

class Data:
name = 'Ram'

  def __init__(self,age,salary):             ##Constructor
       self.age  = age
       self.salary = salary
  def show(self):
     print(self.age)
     print(self.salary)

obj = Data(29,3000)
print(obj.name)

obj.show()

Guide to crack GSOC(Google summer of code).

Tyagiquamar — Sat, 21 Jan 2023 12:25:19 +0000

Google Summer of Code (GSOC) is a highly competitive program that provides students with the opportunity to work on open-source projects during the summer. To crack GSoC, it's important to have a solid understanding of the technology and programming languages that are relevant to the project you're applying for, as well as a strong portfolio of related work.

Here are a few resources that can help you to crack GSoC:

The GSoC website: The official website provides detailed information about the program, including the application process, timelines, and frequently asked questions.

GSoC organization's website: The website of the organization you are applying to will have more specific information about the project you are applying for and their requirement.

Open-source community: Participating in open-source communities is a great way to gain experience and to learn about different projects and technologies. Participating in the community will give you the opportunity to work on real-world projects and to learn from experienced developers.

Study material: There are many resources available online to help you learn about different technologies and programming languages, such as tutorials, documentation, and online courses.

Mentors: Reach out to the mentors of the organization and ask for guidance. They may be able to provide you with valuable advice and resources to help you prepare for GSoC.

Ultimately, cracking GSoC requires a combination of technical skills, passion for open-source, and good communication skills. By utilizing these resources and putting in the time and effort to learn and practice, you can increase your chances of success in the program.

Using coding pattern for dsa.

Tyagiquamar — Sat, 21 Jan 2023 12:19:49 +0000

Using coding patterns to crack coding interviews is a powerful strategy that can help you to stand out from other candidates. Coding patterns are common solutions to common problems, and they can be used to solve a wide variety of coding challenges. By understanding and mastering these patterns, you can improve your chances of success in technical interviews.

One effective way to use coding patterns in interviews is to practice solving problems that are similar to the types of questions that are commonly asked in interviews. This will help you to become more familiar with the patterns and to understand how to apply them in different situations. Leetcode is a great resource for this, as it offers a wide variety of problems that are similar to those found in technical interviews.

Another important aspect of using coding patterns in interviews is to understand the trade-offs and limitations of each pattern. This will help you to make informed decisions about which pattern to use in a given situation and how to optimize your solution.

It's also important to understand how to communicate your thought process and solution clearly to the interviewer. This is crucial as it will showcase your understanding of the problem and your ability to think through the problem and explain it well.

In conclusion, using coding patterns to crack coding interviews is a powerful strategy that can help you to stand out from other candidates. By practicing similar problems, understanding trade-offs and limitations of each pattern, and clearly communicating your thought process, you can improve your chances of success in technical interviews.

Guide for using Leetcode.

Tyagiquamar — Sat, 21 Jan 2023 12:17:28 +0000

Leetcode is a popular platform for preparing for technical interviews and improving your coding skills. It offers a wide variety of problems, ranging from easy to hard, and in different categories such as algorithms, data structures, and databases. To use Leetcode effectively, it's important to have a solid understanding of the coding patterns that are commonly used in the problems.

One effective way to use Leetcode is to start with easy problems and gradually increase the difficulty level. This will help you to build a strong foundation in the basics of algorithms and data structures. It's also a good idea to focus on one category at a time, such as sorting and searching, before moving on to the next.

Another important aspect of using Leetcode effectively is to practice solving problems in different programming languages. This will not only help you to become more proficient in different languages, but it will also help you to understand how to approach problems in different ways.

Once you have a good understanding of the basics, it's time to tackle the harder problems. These problems will often require you to think outside of the box and come up with new and innovative solutions. It's important to take your time and think through the problem carefully before jumping into the solution.

Another way to increase your coding skill is to practice solving problems in a timed setting. This will help you to improve your speed and efficiency, which are important skills for technical interviews.

Lastly, it's important to review your solutions and look for ways to improve them. This will help you to understand the problem better and to learn from your mistakes.

In conclusion, using Leetcode effectively requires a combination of practice, focus, and perseverance. By starting with easy problems, focusing on one category at a time, practicing in different languages, tackling harder problems, and reviewing your solutions, you can improve your coding skills and increase your chances of success in technical interviews.

Practice Data Structure and Algorithm effectively.

Tyagiquamar — Sat, 21 Jan 2023 12:13:21 +0000

Data structures and algorithms are crucial concepts in computer science, and mastering them is essential for any software developer. However, it can be challenging to know where to start and how to practice effectively. In this blog post, we will discuss some tips on how to practice data structures and algorithms to become proficient in them.

Start with the basics

Before diving into advanced data structures and algorithms, it is essential to understand the basics. This includes understanding the different types of data structures, such as arrays, linked lists, stacks, queues, and trees. It also includes understanding the basic algorithms, such as sorting and searching algorithms.

Use online resources

There are many online resources available that can help you learn and practice data structures and algorithms. Websites like HackerRank, LeetCode, and CodeForces offer a wide range of problems that you can solve to improve your skills. These problems range from easy to challenging, so you can start with the easy ones and work your way up.

Practice coding challenges

Another way to practice data structures and algorithms is to participate in coding challenges. These challenges can be found on websites like CodeForces, TopCoder, and CodeSignal. These challenges are great for testing your skills and getting feedback on your code.

Implement data structures and algorithms from scratch
One of the best ways to practice data structures and algorithms is to implement them from scratch. This will help you understand how they work and how to use them effectively. You can start by implementing basic data structures like linked lists and stacks and then move on to more advanced data structures like trees and graphs.

Read books and articles

Reading books and articles on data structures and algorithms can also help you improve your skills. There are many books available that cover the basics of data structures and algorithms, as well as more advanced topics. Reading these books can help you understand the concepts better and give you a deeper understanding of the subject.

In conclusion, practicing data structures and algorithms is crucial for any software developer. By starting with the basics, using online resources, participating in coding challenges, implementing data structures and algorithms from scratch, and reading books and articles, you can improve your skills and become proficient in data structures and algorithms. With consistent practice, you can become an expert in these concepts and excel in your career as a software developer

DSA Blind75, 2 Pointer Algo

Tyagiquamar — Tue, 13 Sep 2022 15:00:22 +0000

On the second day of blind 75. I learnt about 2 pointer technique.
it uses two pointer two reduce iterations to one.
When to apply two pointer/identify

Used in array, strings etc.
Used if input is sorted and we are comparing.
Swapping, partition, removing duplicate or palindrome.

Explaination:-
https://medium.com/@timpark0807/leetcode-is-easy-two-pointers-90b9b0f2eb43
https://youtu.be/KLlXCFG5TnA

Problems done
1.Two sum.
2.Palindrome string.
2.removing duplicates from sorted array.

Beginning of a new journey

Tyagiquamar — Sun, 11 Sep 2022 11:21:20 +0000

Hello everyone, this is my first dev post. I have started my journey to become a software engineer. Currently as being a CSE student i am learning DSA. I also want to learn flutter after doing dsa.