Introduction

Syntax is the set of rules that defines how a Python program must be written so that the interpreter can understand it. In Python, syntax is clear and intuitive, but it also has stricter rules than some other languages—especially around indentation and structure. In this article, we’ll walk through Python’s basic syntax, including how to execute code, indent properly, define variables, and add comments.

Executing Python Code

You can run Python code in one of two main ways:

1. In an interactive prompt: type commands directly (for example, print("Hello, World!")) and see immediate output.
2. In a script file: write code in a file ending with .py, and execute it via your command line (e.g. python myfile.py).

These methods allow flexibility: you can experiment quickly via the prompt, or build fuller programs with scripts.

Python Indentation

One of the most important syntax rules in Python is indentation. While many languages use braces {} or keywords to define blocks, Python uses whitespace (spaces or tabs).

1. Indentation indicates a block of code (for example, under if, for, while, function definitions, etc.).
2. Each line in the same block must use the same amount of indentation.
3. The exact number of spaces is up to you (commonly 4 spaces), as long as consistency is maintained.

Example:

If you skip or mess up indentation:

Python will raise a syntax error.

Also, mixing different indentation levels in the same block leads to errors:

Python Variables

In Python, you don’t need to explicitly declare a variable’s type. A variable is created when you assign a value to it.

Examples:

Here, x becomes an integer variable, y becomes a string. The assignment creates them.

You don’t need a separate “declare” step like in some languages.

Comments in Python

Comments allow you to embed explanations or notes in your code that the interpreter ignores. These are extremely useful for documentation and clarity.

1. Single-line comments begin with #. Everything after the # on that line is ignored.

1. Python also allows multi-line comment-like blocks using triple quotes (""" or ''') in contexts like docstrings—but those are more than just comments (they’re often used as documentation strings).

Best Practices & Tips

1. Use 4 spaces per indentation level (this is common convention).
2. Never mix tabs and spaces in the same file or block.
3. Add comments to explain non-obvious logic, but don’t over-comment trivial lines.
4. Use meaningful variable names rather than cryptic ones.
5. Test small snippets often to ensure syntax is correct.

Summary

Python syntax is designed to be readable and intuitive. However, it enforces strict rules—especially about indentation and structure. Understanding how to properly indent code, declare and assign variables, and comment effectively is foundational for writing correct, maintainable Python programs.