Lab 4 Predicates and Conditionals

Goals

• Practice writing predicates
• Practice with conditionals
• “Divide, Solve, and Combine” (DSC): functions with conditionals

Lab Setup

• Find your partner
• Download lab04.zip which includes the starter code for non-exercise parts of the lab
• Extract that zip file and move the resulting lab04 folder into your cs111 directory on your desktop.
• Open Thonny and view the lab04 files

Table of Contents

• Lab 4 Home
• Part 1: Exercises
• Part 2: More Conditionals Practice
• Knowledge Check

Big Questions

• What is a predicate, and how can you build a complex predicate out of multiple simpler predicates?
  Show Answer

  A predicate is a function that always returns a boolean value. To build a complex predicate from simple ones, the complex predicate function should call the simple functions and combine their result values using boolean operators into a single boolean that it can return.
• What is the difference between writing a series of if statements and a single if statement with multiple elif parts?
  Show Answer

  A series of if statements operate independently, and it's possible for more than one to trigger. A chain of if/elif statements guarantees that only the first statement whose condition is true will trigger, and others will be skipped even if their conditions are also true.