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A Beginner’s Guide to Python 3 Programming

  • November 3, 2023
  • 15 min read
A Beginner’s Guide to Python 3 Programming

Do you want to learn an easy programming language with simple syntax?
Well, Python is your answer. It is a simple and easily readable programming language. It has enormous applications in the market. The language has become one of the top programming languages, replacing C and Java.
Therefore, in this Python 3 Programming guide, we will let our readers know about everything related to Python. This How to Guide provides a piece of complete information on the history of Python and how to install it on different operating systems. Moreover, you can also learn how to start coding with Python straightforwardly and understandably.
Moreover, we have given easy exercises on simple codes of variable declaration, loops, condition statements, and functions. This will provide you a hands-on practice on almost all the most used pieces of code.  Go through the whole article to learn Python and start practicing the simple codes.

What is Python 3 Programming, and why should beginners learn it?

Python 3 is the updated version of the high-level language Python. The language is easy to write and does not need a compiler, as it uses an interpreter to test the code. It is a good choice if you are working on data analysis because of its supportive library, such as Numpy and Pandas. It is also useful for scientific computing. However, the language has a wide range of applications in different areas and projects.

In Python, the interpreter checks the code line-by-line and interprets it. If you have seen the Python code, you must know it is way simpler than Java and C++. The Code for the very famous “Hello Word” is:

Print (“Hello World”)

The Advantages of Learning Python

There are several advantages to learning Python, some of which are given below:

  • The language has simple and easy-to-learn syntax. You can learn it and read it without any difficulty.
  • Moreover, the language has an extensive standard library along with third-party libraries to support the program. The vastness of the library makes it an excellent choice for different applications. 
  • It has the features of both object-oriented and procedural language. It further supports multiple other programming paradigms. 
  • There is no need for compilation in the language. It uses an interpreter to interpret the codes line-by-line. This means that you can test your code right after creating it.
  • It is suitable for data analysis applications. If you are someone related to data analysis, [you must learn it.]

Automation with Python Scripting:

Python’s scripting capabilities empower developers to automate repetitive tasks, enhancing efficiency and reducing manual intervention. Python development services utilize scripting to streamline processes, whether it’s automating system tasks, data processing, or building custom automation solutions tailored to specific business needs.

History of Python and Its Popularity

Python is a high-level programming language that was developed by Guido Van Rossum in 1990. However, the version of Python 3.0 came in 2008. It is one of the most popular general-purpose programming languages widely used for several programs. The concept behind the language was to create an easy-to-read and more straightforward programming language.

 The developer emphasized readability and fewer lines of code. This is why it has become the fourth most popular programming language in 2022. The language has taken Java and C because it is a simple and more paying platform. Moreover, it is an open-source programming language; you can make changes anytime, and freely available.

Setting Up Your Python Environment

To install Python on your system, follow the instructions according to your operating system. 

Installing Python for Windows

1: Download Python Installer:

  1. Download Python from the Python Page,  
  2. Download the suitable executable file for your system, such as 64-bit or 32-bit.

2: Execute the Installer

  1. Double-click on the .exe file in the folder to launch the Python installer.
  2. Check the “Install launcher for all users” checkbox to allow all system users to use Python.
  3. Click Add Python.exe to Path to launch your installer; you can use it on the command prompt.
  4. If you are new and cannot understand the instructions, click “install now” and go to step 4.
  5. Then Choose the following options accordingly.
    • Click Recommended in front of Documentation.
    • Pip, if you want to work with NumPy or Pandas.
    • If you will use IDLE, click on tcl/tk and IDLE.
    • For learning and testing, click the Python test suite.
    • To launch Python from the command line, use py launcher.
  6. Then, go to advance dialogue by clicking next.
  7. Then choose the options according to your work requirements.
  8. Then, Click the Install Button to start the installation.
  9. You will see the “Setup was successful” window when the installation is done.

3: Add Python to your Environment

If you have already selected the option to add Python to the environment, skip this. This step is optional; you can skip it according to your requirements.

4: Make Installation Verification

If you want to see that your python is successfully installed, there are two ways. You can check it by command line or use an integrated development environment. To do that, follow the instructions given below:

  • Open Command Prompt and write 

Python – – version

  • If the output shows a version of Python, such as Python 3.10.10, your installation is accurate.

Installation for the Window is done.

Installing Python for MacOS

There is news Python 2.7 is already installed on your Mac OS. However, the version is now retired. Python 2.7 is not recommended for any development. Therefore, you need to upgrade it. 

1: Download Python Installer

Download the installer by following the instructions given above in the window section.

2: Launch the Installer

  1. Launch the installer and select the required options as given in the above section. Moreover, you have to enter the password of your Macbook to allow the installer to start working. 
  2. After the completion of the installation, you will see a window in the Python folder. Open IDLE and write a code to see if it works correctly. 

Installing Python For Linux

To install Python for Linux, use the following instructions:

1: Development Package 

You need a development package to install Python on your Linux OS. There are two packages available:

  1. Debian 
  2. Adora 

2: Download and Configure the Python

  • You need to download the latest version of Python and extract tar files to start installation. Configure the code and follow the same steps. 
  • After finishing the installation, verify if Python is accurately installed or not.
  • Then create the virtual environment, if you need one.
  • Basic Input and Output

How to take user input and display output in Python

In Python, it is not difficult to give inputs and get output from the interpreter. We use a simple code, such as input() and output(), to provide display commands. 

Python I/O

If you are familiar with coding, you must know about the Input Output stream, where the user inputs the program to get a relevant output.

python 3 programming

Get Output from Python

Programmers use print() statements to get the output from the data. You just simply need to write on your IDLE window:

Print( “Welcome to my Python Guide” )

And you will be able to see output in the output section.

Give Input to the Python

Now if you want to get a customized output or a calculation, you have to give an input to the program. The input code is like:

Post = input (“Enter your designation”)

Output (“I am working at the post of” + post)

Sometimes the programmer works on more advanced or a bit complicated code by using specific variables and data types, which you will learn in the next section.

Variables and Data Types

When working with different values and more than one number, data types and variables help you a lot. 

Variable

It is memory location or space in the memory where you can store your values. You can store multiple values in one variable. By doing so, there is no need to declare each value individually. It’s an easy way to assign input. Moreover, the memory location will be free when the interpreter is not using that value.

To declare a variable in your Python program, use the following code:

X= 45                  A= “Jonnas”

There are some instructions that you need to keep in mind while working with the variables in Python.

  • The name of the variable will only start with a syllable/character. Do not start it with a 
  • Use only alpha_numaric characters
  • Do not use any special characters.
  • Most importantly, variables are case-sensitive. If you change the case of the variable, the interpreter will mark it as an error.

DataTypes for Python

Programmers use several data types in Python 3 programming to work with different types of programs. For example, characters, numeric, tulip, set, string list, etc.

You can see different data types in the following table:

python 3 programming

1. Numeric DataType in Python

There are four types of numeric data, integer, float, boolean, and complex numbers.

  • Integers: It is for the whole numbers. You can declare it as given below.

X = 100           y = 135

  • Float: It represents the decimal values or values with a point.

x= 25.87    y = 19.05

  • Complex Numbers: When there is an imaginary value in your program, use a complex number. Use ‘ j ‘ at the end of the statement to donate the imaginary value.

X = 16 + 7j

  • Boolean: When there are two possible outputs, use a boolean datatype. For example,

Num = 9 < 8

2. String DataType in Python

While working with the Unicode values, you use strings. In Python, any single character or multiple characters fall under the datatype of a string. To declare the string, use single or double quotes in the code.

Name = “Jasson”

name = ‘edureka’
name.upper()
#this will make the letters to uppercase
name.lower()
#this will make the letters to lowercase
name.replace(‘e’) = ‘E’
#this will replace the letter ‘e’ with ‘E’
name[1: 4]
#this will return the strings starting at index 1 until index 4.

3. List DataType in Python

The list dealers the data in the collection. Moreover, you can store multiple data types in one list, such as:

My_list = [ 5,7,9,7,56, “My Score”]

4. Tulips DataTypes in Python

It also works like a list. However, the values in Tulip are unchangeable. You can only access them by using fixed index numbers.

mytuple = (10,14,20,14,40,50)
mytuple.count(14)
#the output will be 2
mytuple.index(40)
#the output will be 5.

5. Sets DataTypes in Python

To declare unordered data, we use sets with curly braces. Such as:

Set ={ 2,5,3,7,1,10}

These values do not have index numbers on them.

6. Dictionary

It is a collection array in Python. The values in the dictionary remain unordered and changeable with key values. You can access them by using the key. Use curly brackets to declare the dictionary, such as given below:

mydictionary = { ‘python’: ‘data science’, ‘machine learning’ : ‘tensorflow’ , ‘artificial intelligence: ‘keras’}
mydictionary[‘machine learning’]
mydictionary.get(‘python’)

7. Range

It is usually used for loops. Just as in the example given below:

for x in range(10):
print(x)
Python 3 Programming

Your First Python Program

Until now, you must have known much about Python 3 Programming and its basic introduction. So, write your first code with us, as we are here for your guidance on every step.

In the previous section on Input/output, you learned how to give and get input and output, respectively. Now we will see a difficult one with numeric values and their addition.

Add Two Numbers

You must declare two variables with a numeric datatype and assign them values. Follow the given code:

#Declare two variables and assign them numeric values
Num1 = 23
num2 = 45
# Write code to add the values
sum = num1 + num2
# Write the code to add both values and display them in the output section
print(‘The sum of {0} and {1} is {2}’.format(num1, num2, sum))

Conditional Statements

Anyone with a CS or IT background can understand the meaning of conditional statements. You can use them whenever two possible answers exist to a given problem. For example, if you add a natural number and ask the interpreter whether it is odd or even, you will use conditional statements. 

You must use if/else keywords to tell the interpreter you are using a condition. If there are two possible answers, use if/else; for more than two, use if/else/ if else.

Follow the code to understand the process of a conditional statement:

#To take input from the user, write the code
num = int (input (“Enter a number: “)
#Apply Conditional statement to check whether the number is even or odd
if (num % 2) == 0:
print (“ Your number is even”)
else:
print (“Your number is Odd”)

Loops in Python

Generally, the loops are a sequence of instructions that keep working until a specific condition gets met. The method is helpful when there is a need to do repetitive tasks, such as adding numbers from 1 to 100. Now that is time-consuming and tedious if you have to do it manually. Here comes the loops. 

Moreover, there are two types of loops,  For and While loops.

For Loop

To print the first four digits from the whole number, use the code given below:

# Declare a variable and set the range to 4
Numbers = range(4)
# iterate from i = 0 to i = 3
for i in Numbers:
print(i)

While Loop

To display one to five natural numbers on the screen, use the following code:

# Declare 2 variables, one for the initial value and the other for the final value.
i = 1
n = 5
# place the while loop code, where i = 1 and n = 5
while i <= n:
print(i)
i = i + 1
You will see the number on the screen just as given below
Output:
1
2
3
4
5

Functions in Python

Functions are the blocks of codes that only run when you call. Moreover, they only perform a specific task; the control returns to the interpreter when it’s done. There is one thing about functions it only runs when called outside the function. To add two numbers in a function, use the following code:

# Write a function with two arguments

def add_numbers(num1, num2):
sum = num1 + num2
print(‘Sum: ‘,sum)

Error Handling

Use of try blocks in the code will allow you to test any block or portion of code to see if there is an error in it or not. The code consists of two keywords, try and accept.

Learn error handling by using the following code:

try:
numerator = 10
denominator = 0

result = numerator/denominator

print(result)
except:
print(“Error: Denominator cannot be 0.”)

# Output: Error: Denominator cannot be 0

File Handling

You can use Python code to read or write any file in the system. Some functions and methods are given in the Python library to read and edit the file. For example, you use the open() method to open any file. The code will be

Myfile = open( “myfile1.txt”)

For complete opening and closing of a file, use the code:

# open a file file1 = open(“test.txt”, “r”)  
# read the file read_content = file1.read() print(read_content)  
# close the file file1.close()

Introduction to Libraries and Modules

Python modules are the collection of relevant code packed together in a program. Python codes can be long enough to understand and sometimes complicated for developers and programmers. 

However, by using modules, you can break these complicated tasks into short pieces of code. Three types of modules are given below:

Pre-Defined Module

These modules are built-in in the Python library. You just need to call these modules, and then you can use any relevant function. Such as, by using the module “import,” you can call any function like math. The code will be import math. These built-in programs are written in C language. 

# import the square root and factorial function from the library
from math import sqrt, factorial

# printing the square root of 16 using sqrt() function
print(‘The square root of 16 = ‘,sqrt(16))

# printing the factorial of 5 using factorial()
function print(‘The factorial of 5 = ‘,factorial(5))

User-Defined Modules

The programmers and users create these modules for their use. Python is an open-source language; it allows programmers to develop blocks of code for their use and make customizations in the language. A user-defined code is given below:

Module.py  

def sampleFunction(givenValue):
print(“The values passed to the function is:”, givenValue)

External Modules

Modules that the programmer downloads from outside. They do not exist in the library nor created by any Python user. You have to install it from the Internet. It is not difficult to install it; just use “pip install module_name.” You can search these modules and use them according to your requirements.

Conclusion

Well, this was it. You have learned the basics of Python. However, it is the practice you need to be an expert in the language. Python is an object-oriented language, which means there is more to learn. There are classes, inheritance, polymorphism, and many other things to learn in Python. But you need to understand the basics first, as in classes, you need functions. So, if you have not developed a complete understanding of functions, you will not be able to understand classes as well. Several sources provide the Python code that you can practice by yourself. Moreover, you can visit Python’s official site for further guidance on Python 3 Programming. There is no doubt that Python is an easy-to-learn and simple-to-use language, but it needs expertise and experience to deal with the bugs and problems.

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