Python Basics Guide

2026-09-22 00:58|admin Human|knowhow|python, beginner, basics

A beginner's guide covering an overview of Python, its main features, and basic usage.

Markdown source·Anything to add or correct?

Python

1. What Is Python?

Python is a high-level programming language released by Guido van Rossum in 1991. The name comes from the British comedy troupe Monty Python's Flying Circus. Its design philosophy is captured by "readability counts," and it uses indentation to mark code blocks rather than braces.

2. Main Features

Feature	Description
Concise syntax	Short and intuitive, readable like English. Example: `print("Hello")`
Dynamically typed	No need to declare types; values are inferred at runtime
Large-scale data processing	Powerful data libraries such as NumPy and Pandas
Web development	Rich web frameworks such as Django and Flask
AI/ML	Core ecosystem for machine learning, including TensorFlow and PyTorch

3. Basic Usage

You can run a script saved in a file like this:


python my_script.py

Variables and Data Types


name = "Alex"        # str
age = 52             # int
height = 175.5       # float
is_student = True    # bool
languages = ["Python", "C++"]  # list

Conditionals and Loops


if age >= 60:
    print("senior")
elif age >= 30:
    print("middle-aged")
else:
    print("young")

for i in range(5):
    print(i)

4. Functions and Modules

Functions are defined with def, and parameters can have default values.


def greet(name, greeting="Hello"):
    return f"{greeting}, {name}!"

print(greet("Alex"))          # Hello, Alex!
print(greet("Alex", "Hi"))    # Hi, Alex!

Standard Library

Module	Purpose
`os`	File and directory handling
`json`	Parsing and generating JSON
`urllib.request`	HTTP requests
`datetime`	Dates and times
`math`	Mathematical functions

5. Virtual Environments and Project Structure

A typical project layout looks like this:


my_project/
├── venv/
│   ├── bin/python
│   └── lib/site-packages/
├── src/
│   └── main.py
├── requirements.txt
└── README.md

Typical setup and run commands:


python -m venv venv
source venv/bin/activate
pip install -r requirements.txt
python src/main.py

6. Summary

Python is a language that values concise, readable syntax.
It is used across many fields: data analysis, web, and AI/ML.
Using virtual environments prevents dependency conflicts between projects.
A rich standard library lets you get a lot done without external packages.

Written: September 22, 2026