Understanding Python Statements, Indentation, and Comments

This tutorial provides a foundational understanding of Python statements, indentation, and comments – crucial elements for writing clean, efficient, and maintainable code.

Table of Contents

1. Python Statements
2. Python Indentation
3. Python Comments

Python Statements

In Python, a statement is a single instruction executed by the interpreter. While typically occupying a single line, long statements can span multiple lines using line continuation (backslashes or parentheses ()). Statements encompass assignments, function calls, loops, and conditional statements.

Examples:

• Assignment: x = 10 (assigns 10 to x)
• Function Call: print("Hello!")
• Conditional Statement:

  
  if x > 5:
      print("x is greater than 5")
  else:
      print("x is not greater than 5")
  

• Loop Statement:

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

Python Indentation

Unlike languages using curly braces {} to define code blocks, Python uses indentation. This determines statement grouping within blocks (if, else, for, while, functions, classes). Consistent indentation is mandatory; inconsistencies cause IndentationError.

Correct Indentation:

if x > 5:
    print("x is greater than 5")
    y = x * 2
else:
    print("x is not greater than 5")

Incorrect Indentation:

if x > 5:
print("x is greater than 5")  # IndentationError
y = x * 2
else:
print("x is not greater than 5") # IndentationError

Use 4 spaces for indentation; avoid tabs.

Python Comments

Comments are explanatory notes ignored by the interpreter. They enhance code readability and understanding. Python offers two types:

• Single-line comments: Begin with #. Anything after # on the same line is a comment.
• Multi-line comments (docstrings): Enclosed in triple quotes (''' or """). Frequently used to document functions, classes, and modules.

Examples:

x = 10  # Single-line comment

'''
This is a
multi-line comment.
'''

def my_function():
    """This is a docstring."""
    pass

Effective commenting is crucial for clean, maintainable code. Keep comments concise and relevant; avoid redundant explanations.