"List Comprehensions" Exercise

Prerequisites

• Lists

Learning Objectives

• Demystify the incredible powers of Python list comprehensions, a powerful data-processing technique

• Practice performing mapping and filtering operations on Python lists

Setup

Create a new Python script called something like "total_comprehension.py" somewhere on your computer, perhaps your Desktop.

Open that file with your text editor and place inside the following contents:

# total_comprehension.py

my_numbers = [1, 2, 3, 4, 5, 6, 7]
print("--------------")
print("ORIGINAL LIST:", my_numbers)

print("--------------")
print("TOTAL COMPREHENSION...")

# TODO: write python code here

From within your "base" environment, or any other Anaconda virtual environment, run the script:

python total_comprehension.py

Instructions

Write Python code in the "total_comprehension.py" file which will use the filtering and mapping capabilities of list comprehensions to transform the provided list (i.e. my_numbers) in each of the following ways:

• Use mapping capabilities to multiply each number by 100 (e.g. [100, 200, 300, 400, 500, 600, 700])

• Use filtering capabilities to return only the numbers greater than three (e.g. [4, 5, 6, 7])

• Use filtering capabilities to return only the numbers greater than eight (e.g. [])

• Use mapping and filtering capabilities to return only the numbers greater than three, each multiplied by 100 (e.g. [400, 500, 600, 700])

Example final output:

--------------
ORIGINAL LIST: [1, 2, 3, 4, 5, 6, 7]
--------------
TOTAL COMPREHENSION...
--------------
MAPPED LIST: [100, 200, 300, 400, 500, 600, 700]
--------------
FILTERED LIST W/ MATCHES: [4, 5, 6, 7]
--------------
FILTERED LIST W/O MATCHES: []
--------------
MAPPED AND FILTERED LIST: [400, 500, 600, 700]

Solution