Truthy and Falsy Values

Everything else is truthy. This includes things that might surprise you: All are True. Non-empty strings, non-empty containers, and non-zero numbers are truthy. Idiomatic Boolean Checks Pythonic code uses truthy/falsy values directly instead of explicit comparisons: These truthy/falsy patterns appear constantly in algorithmic code. Here is a valid parentheses checker using stack truthiness: Tree inorder traversal: None vs Falsy Problem: 0 is a valid return value but falsy. Wrong check: Correct check: