Indentation is the leading whitespace that shifts code to the right. In Python, it marks which statements belong inside a block, such as a while loop. When a loop begins, indent every line it controls—four spaces is the practical rule. section 4.0 section 4.1
When adding a loop to a menu function:
- Put the loop-controlled statements four spaces to the right. section 4.0
- Indent statements nested inside an if or else block farther to the right. section 4.0
- Use the editor’s Check button to catch a missing indented block before running the program. section 4.0
A correctly indented menu loop
The statements belonging to while True are shifted right, and the statements belonging to if are shifted right again:\n\nwhile True:\n choice = input(prompt)\n if choice in allowed_answers:\n answer = choices[int(choice) - 1]\n break\n else:\n print("Enter a valid choice")\n answer = ''
A missing indentation can stop the program with an “expected an indented block” message. Fix the layout, check again, and then run the menu to confirm that the loop behaves as intended. section 4.0
YOUR TURN
Add a while loop to your own function. Deliberately leave one line unindented, click Check, and then move it into the block. Try making and fixing another indentation error. section 4.0
