Making Decisions
8 min · Python
Run different code depending on whether something is true.
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Every program you've written so far runs the same lines in the same order every single time. Real programs need to react differently depending on the situation — show a "Game Over" message only if the player's health hits zero, apply a discount only if the cart total is high enough. That's what decisions (also called conditionals) are for.
Programs make choices by checking whether something is true or false — a value Python calls a boolean. You compare values with comparison operators like > (greater than), < (less than), >= (greater than or equal), <= (less than or equal), and == (equal to). Notice == uses two equals signs — a single = is for assignment (storing a value), while == is for comparison (asking a question). Confusing the two is one of the most common beginner bugs, though Python will usually catch it for you in an if with a clear error.
An if statement runs the indented block beneath it only when its condition evaluates to true; if the condition is false, that block is skipped entirely and the program moves on. Run this:
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