Python Syntax

What You’ll Learn

You will learn about Python’s unique syntax, particularly its use of indentation to define code blocks.

Indentation is Mandatory

In many programming languages, curly braces {} are used to define blocks of code (like in HTML, CSS, JavaScript). Python uses indentation (whitespace at the beginning of a line) instead.

Basic Example

# Correct Indentation
if 5 > 2:
    print("Five is greater than two!")

If you skip the indentation, Python will throw an error:

# This will cause an IndentationError
if 5 > 2:
print("Five is greater than two!")

The Number of Spaces

The number of spaces is up to you as a programmer, but it must be at least one. The most common standard is 4 spaces. You must use the same number of spaces in the same block of code.

if 5 > 2:
    print("First line")
    print("Second line") # This is fine, both have 4 spaces

Line Endings

Python doesn’t require semicolons ; at the end of statements. A new line indicates the end of a command.

Common Mistakes

• Mixing tabs and spaces: Pick one (spaces are preferred) and stick to it. Modern editors like VS Code handle this automatically.
• Inconsistent indentation within the same block.