Python Syntax

Python's syntax is famously readable. The most distinctive rule: indentation defines blocks. No curly braces, no begin/end.

Indentation = block

if 5 > 2:
    print('Five is greater than two')      # 4 spaces — same block
    print('Still in the if block')
print('Out of the if block')

Pick 4 spaces and stick with it across the whole file. Mixing tabs and spaces is a hard error.

Comments

# Single-line comment

"""
A triple-quoted string used as a block comment.
Technically a string literal, but Python ignores it
when it's not assigned to anything.
"""

Statements end at the newline

No semicolons. To put two statements on one line you'd use a real ; — but almost no Python code does.

Naming

Example

# Indentation defines blocks (4 spaces by convention)
if 5 > 2:
    print('Five is greater than two')

Exercise

Test yourself