The if Statement

Concepts covered: pyIfElse

Basic if Syntax Both indented print statements run because age is 21, which is greater than or equal to 18. The final print statement runs regardless of the condition because it is not indented under the if. When Conditions Are False When the condition evaluates to False, Python skips the entire indented block and continues with the next unindented line: Since 15 is not greater than 30, the condition is False and both indented lines are skipped. Only the final unindented line executes. Conditions and Booleans Each comparison operator serves a different purpose. Here is a quick reference for the six operators you will use most often in conditional logic: Collection Conditions Conditions work with any data type, not just numbers. You can compare strings, check membership in collections, and

About This Interactive Section

This section is part of the Control Flow: Beginner lesson on DataDriven, a free data engineering interview prep platform. Each section includes explanations, worked examples, and hands-on code challenges that execute in real time. SQL queries run against a live PostgreSQL database. Python runs in a sandboxed Docker container. Data modeling problems validate against interactive schema canvases. All content is framed around what data engineering interviewers actually test at companies like Meta, Google, Amazon, Netflix, Stripe, and Databricks.

How DataDriven Lessons Work

DataDriven combines four interview rounds (SQL, Python, Data Modeling, Pipeline Architecture) with adaptive difficulty and spaced repetition. Easy problems get harder as you improve. Weak concepts resurface until you master them. Your readiness score tracks progress across every topic interviewers test. Every lesson section ends with problems you solve by writing and running real code, not by picking multiple-choice answers.