Lesson 6.02: Dictionaries Methods

Learning Objectives

Students will be able to...

• Define and identify: pop, default value
• Update values in a dictionary
• Add values to a dictionary
• Remove values from a dictionary

Materials/Preparation

• Do Now
• Lab - Word Counter
• Solution
• Associated Reading - section 5.2 of Book
• Read through the do now, lesson, and lab so that you are familiar with the requirements and can assist students

Pacing Guide

Instructor's Notes

1. Do Now
   • Display the Do Now on the board.
   • Students type code that edits dictionaries by modifying, adding, or removing key:value pairs.
2. Lesson
   • Discuss part 1 of the Do Now.
     • Describe that you can update a value in a dictionary in a similar way to how you would update a value in a list.
   • Discuss part 2 of the Do Now.
     • Note that you can add values to a dictionary by using the same syntax.
     • Review: How might you check if a value was in a dictionary before adding it?
   • Discuss part 3 of the Do Now
     • Review what pop does, as well as what the second argument does.
       • The second argument in pop is described as the default value. This is the value that will be returned if the first argument is not in the dictionary.
3. Lab
   • Students will create a word count algorithm that will count the number of words in a list of words.
4. Debrief
   • Talk about any confusion the students had. Discuss additional ideas of how dictionaries might be useful.

Accommodation/Differentiation

Some students may need to be explicitly reminded of the in keyword to check if a certain key is in their dictionary.