Introduction to Python Programming - Getting Started

Introduction

Python is a general-purpose, high-level programming language released in 1991 by Guido van Rossum. A high-level language is closer to human language, while low-level languages are closer to machine language (binary 0s and 1s).

Python is an interpreted language meaning that its code runs without needing compilation. Code written in languages like C/C++ requires and uses a compilation step to generate some artifacts. One such artifact is executable files (ending with .exe in windows and .out in linux).

Python is also a dynamically-typed language. A fancy way to say that python variables can hold different value types anywhere in a program. For example:

# age is an integer
age = 45

# age is now a string
age = "Forty-five"

In statically-typed languages like C++, Java, etc., a variable cannot be set into a different type after it has been created (at least without the use of some tricks).

Why would you want to learn python

Python is a great programming language because:

• It is popular - increases the chances of getting python jobs. Its popularity also makes it easy to get help when faced with problems.

• It has versatile use - web, data analytics, ML, desktop, security, etc., and

• It has easy-to-learn, concise, and readable syntax.

• It is interpreted and

• Supports programming paradigms (procedural, object-oriented, functional).

• It is an excellent place to learn programming concepts before moving on to other languages.

I said python is easy?

Let's print "Hello world" in python:

print("Hello world")

Here's an equivalent ceremony in C/C++:

#include <stdio.h>

int main() {
  prinf("Hello world\n");
}

Java too:

class PrintHello {
   public static void main(String[] args) {
       System.out.println("Hello world");
   }
}

Why you wouldn't want to learn/use python

• Python might be very slow for some use cases such as systems programming and production-grade machine/deep learning models. Well, this slowness is generally a problem with interpreted languages. In such cases, languages like C/C++, Rust, and Java are faster.

Installing Python

• Go here to download python for your operating system.
  Then click the download file and follow the prompts to install it.

• In the installation prompt, check Add Python to PATH so you can assess the program anywhere when using the command line and make it easier for code editors to find python.

• Optionally, install a code editor like VSCode or an IDE like Pycharm. They make writing python easier.

Tip: VSCode is lighter. Use it primarily when you use a not-so-fast machine.

Testing Your Python Installation

• At the command line/shell, type python and press enter. The python command displays the python shell shown in the image below!
  

• Type name = "Hello" and press enter.

• Type name and press enter. You will see the content of the name variable printed out on the console.

• Optionally, search for the python manual and pin it to your taskbar. The documentation is a great way to learn python.

Running a Python program

You can run a python program directly in an interactive python shell or REPL. Running python at a python shell is a quick way to run simple or one-time programs.

>>>2 + 2
4
>>>6 + 8
14
>>>"Hello world"
'Hello world'

However, it is best to write the code in a python file (a file ending in .py) for large programs. Execute the python file at a console by running python whatever_name_it_was.py. Code editors and IDEs can simplify the running of python codes.

Conclusion

Python is a great place to start your programming journey as it is relatively easy to learn.