HOMEWORK 01: FUNCTIONS & STATEMENTS SOLVED

Introduction

The goal of this homework is for you to allow your TAs to get to know you as well as allow you to practice and understand how to write functions and evaluate expressions. Part 1 is simply uploading a photo of your face given the specifications listed. Part 2 will consist of 7 functions for you to implement. You have been given HW1.py to fill out with instructions in the docstrings. However, below you will find more detailed information to complete your assignment. Read it thoroughly before you begin. You have until Thursday, August 31st to complete this assignment.

String Formatting

A concept that will be very helpful for this homework is string formatting. The purpose of this is to allow you to manipulate statements using variables so that values can change within depending on the different outputs of the function. In order to do this, let’s use an example where I ask the user for their name, and then print it out. Try this examples out:

name = input(“What is your name?”)

print(“Your name is {}”.format(name))

num = 3.141592

print("pi is {:.2f}".format(num))

What is happening is that anywhere in a string, I can put {} to indicate a placeholder for a variable. After the end quotation marks, I would write .format() to the end, and inside the parenthesis will be the variables that you want to include, in the order that {} are placed in the sentence. Read this for more info: [ https://pyformat.info/ ]


Authors: Lucille Wang | Report Issues: lucillewang@gatech.edu

HOMEWORK 01: FUNCTIONS & STATEMENTS
2


print vs. return

Distinguishing the difference between print and return is extremely important now and in the future. Print takes a python object and outputs a printed representation of it in the output window. You can think of a print statement as something for the person. Printing has no ongoing execution of a program. It doesn’t assign a value to the variable. For example, if you have this function:

def printFunc():

print(2)

In your shell, you should get this:

    • a = printFunc()

2
    • print(a)
None

However, return is used for a function when you need to save the result of the function to be used for later. By returning a value, the function is producing a value for use by the program, in particular for use in the part of the code where the function was invoked. For example, if you have this function:

def returnFunc():

return 2

In your shell, you should get this:

    • b = returnFunc()

    • print(b)
2

Read this for more info: [ http://interactivepython.org/runestone/static/pip2/Functions/Printvs.return.html ]

Part 1: Mugshot


Find a picture of yourself. Crop the picture to include just your face. (Your face must be at least 1/3 of the image.) Resize the picture to be exactly 300 pixels by 300 pixels in size. Save the picture as a JPG, using your first and last name as the file name, (e.g. Jay_Summet.jpg). Submit this picture to t-square. You may use an image editing tool you are familiar with to manipulate your mugshot picture. If you do not have a preference, we recommend using the GNU Image Manipulation Program (GIMP): http://www.gimp.org/downloads/












Authors: Lucille Wang | Report Issues: lucillewang@gatech.edu

HOMEWORK 01: FUNCTIONS & STATEMENTS
3


Part 2: Functions

Function name (1): weight_on_mars

Parameters: N/A

Return value: N/A

Description: Write a Python program which accepts your weight on Earth and prints out your weight on Mars. Assume that the weight inputted is not negative. The weight can be
    1. Ask the user to input their weight on Earth in pounds.

    2. Your weight on Mars is 0.38 of your weight on Earth. For example, if you weight 100 pounds on Earth, you would weigh 38 pounds on Mars.
    3. Print out the answer in the format: “At a weight of 100 pounds on Earth, you would weigh

38 pounds on Mars”.

Test Cases (not an exhaustive list):

    1. >>> What is your weight on Earth (in pounds)?

150
At a weight of 150 pounds on Earth, you would weigh 57 pounds on Mars.

2. >>> What is your weight on Earth (in pounds)?

100.8
At a weight of 100.8 pounds on Earth, you would weigh 38.304 pounds on Mars.

Function name (2): volume_of_cone

Parameters: N/A

Return value: volume of the cone

Description:

Write a function that takes the radius and height from the user and calculates the volume of a cone.

    1. Get the length of the radius of the cone from the user.

    2. Get the height of the cone from the user.

    3. Calculate the volume of a cone with the radius length and height entered by the user using the following formula:
=    ∗    0 ∗ ℎ      ℎ  

3
        4. Return the volume of the cone rounded to three decimal places.

Hints:

    • You can round a number by using the round(number, number of decimal places) function or by using string formatting. For example, you can round 56.14523 to 56.145 by

doing round(56.14523,3). [ https://docs.python.org/3/library/functions.html#round ]

    • Importing the math module to get the value of π might be helpful. In other words, you must use the math module π. You will lose points if you hardcode 3.14.

Test Cases (not an exhaustive list):

    1. >>> a = volume_of_cone()
        ◦ What is the length of the radius of the cone? 3

        ◦ What is the height of the cone?

4
    • print(a) 37.699

Authors: Lucille Wang | Report Issues: lucillewang@gatech.edu
HOMEWORK 01: FUNCTIONS & STATEMENTS
4


    2. >>> b = volume_of_cone()

        ◦ What is the length of the radius of the cone? 10

        ◦ What is the height of the cone?

2
    • print(b)
209.440

Function name (3): calculate_velocity

Parameters: initial_position, final_position, time

Return value: N/A

Description: Write a function that finds the velocity using the initial position, final position, and time passed in the function.
1.    Calculate the velocity using the following formula:
=    _    –    _


    2. Print the velocity in the following format: “With an final position of 100 meters, initial position of 0 meters, and a time of 80 seconds, the velocity is 12.5 m/s.”

Test Cases (not an exhaustive list):

    1. >>> calculate_velocity(0,100,80)

With a final position of 100 meters, initial position of 0 meters, and a time of 80 seconds, the velocity is 12.5 m/s.

    2. >>> calculate_velocity(2,10,0.5)

With a final position of 10 meters, initial position of 2 meters, and a time of 0.5 seconds, the velocity is 16 m/s.

Function name (4): liquid_converter

Parameters: N/A

Return value: N/A

Description: Write a user-interactive function to convert any number of fluid ounces to the equivalent number of gallons, quarts, pints, and gills.

    1. Get the number of fluid ounces as an integer from the user. You can assume that the user input an int.
    2. Calculate the total number of gallons, quarts, pints, and gills represented by the original number of fluid ounces, using the following information:
        a. There are 128 fluid ounces in a gallon.

        b. There is 32 fluid ounces in a quart.

        c. There are 16 fluid ounces in a pint.

        d. There are 4 fluids ounces in a gill.

    3. Print the calculated number of gallons, quarts, pints, and gills in the following format

(assuming the user entered 6523): “6523 fluid ounces is 50 gallon(s), 3 quart(s), 1 pint(s), and 2 gill(s)”
Hints:

    • The modulus (%) and integer division (//) operators will be very useful for this function. Test Cases (not an exhaustive list):

    1. >>> How many fluid ounces would you like to convert? 6523
6523 fluid ounces is 50 gallon(s), 3 quart(s), 1 pint(s), and 2 gill(s)

Authors: Lucille Wang | Report Issues: lucillewang@gatech.edu
HOMEWORK 01: FUNCTIONS & STATEMENTS
5


    2. >>> How many fluid ounces would you like to convert? 1250
1250 fluid ounces is 9 gallon(s), 2 quart(s), 2 pint(s), and 0.5 gill(s)
    3. >>> How many fluid ounces would you like to convert? 180
        ◦ 180 fluid ounces is 1 gallon(s), 1 quart(s), 1 pint(s), and 1 gill(s)


Function name (5): calorie_counter

Parameters: N/A

Return value: N/A

Description:

Write a function that takes the number of meals and number of miles to calculate a person’s caloric intake in a day.
    1. Get the number of meals a person ate from the user.

    2. Get the number of miles a person ran.

    3. Calculate a person’s caloric intake using the following:

        a. The average calories gained per meal is 500 calories.

        b. A person that has done no exercise has burned about 1600 calories.

        c. The average calories burned per mile of running is 95 calories.

    4. If a person gains the same or more calories than they burn then you should print a positive number. If a person burns more than they gain you should print a negative number.

    5. Print the result in the following format: “After eating 5 meals and running 2 miles, a person gained 2500 calories and burned 1790 calories, leading to an intake of 710 calories.”

Test Cases (not an exhaustive list):

    1. >>> How many meals did you eat today? 4

    • How many miles did you run today? 0

After eating 4 meal(s) and running 0 mile(s), a person gained 2000 calories and burned 1600 calories, leading to an intake of 400 calories.

    2. >>> How many meals did you eat today? 1

        ◦ How many miles did you run today?

1

After eating 1 meal(s) and running 1 mile(s), a person gained 500 calories and burned 1695 calories, leading to an intake of -1195 calories.

Function name (6): paycheck_computation

Parameters: pay_rate, hours_worked, tax_rate

Return value: person’s take home pay

Description: A person’s pay is determined by the hours they worked times the hourly rate. Unfortunately, a percentage of their pay is taken out as taxes. Using the parameters listed above, calculate and return the amount that a person’s paycheck will be for after taxes have been taken out.

    1. The first parameter, pay_rate, contains a person’s hourly pay.

    2. The second parameter, hours_worked, contains a person’s number of hours worked.

    3. The third parameter, tax_rate, gives the amount taken from taxes as a fraction between 0 and 1.

Authors: Lucille Wang | Report Issues: lucillewang@gatech.edu
HOMEWORK 01: FUNCTIONS & STATEMENTS
6


    4. Calculate the person’s take home pay, which is their paycheck total after taxes have been deducted.
    5. Return the person’s take home pay.

Test Cases (not an exhaustive list):

    1. >>> a = paycheck_computation(10,4,0.8)

>>> print(a)
8
    2. >>> b = paycheck_computation(18,40,0.2)

>>> print(b)
576

Function name (7): main

Parameters: N/A

Return value: N/A

Description:

This function has been started for you. It serves as an introduction for conditional statements (learned later in the course). All you have to do is ask the user what function they will like to call and make the function call yourself.

    1. Ask the user to input the number of the function (any number from 1 through 6 should be valid)
    2. Replace the pass statements with your function calls.




































Authors: Lucille Wang | Report Issues: lucillewang@gatech.edu

HOMEWORK 01: FUNCTIONS & STATEMENTS
7


Grading Rubric

-Mugshot: 20 points

File Named Correctly: 5 Points

Correct File Size: 10 Points

Face Recognizable: 5 Points

    • weight_on_mars: 10 points

Correct function header: 2 Points

Prints in the correct format: 3 Points

Correct Value is calculated: 5 Points

-volume_of_cone: 10 points

Correct function header: 2 Points

Prints in the correct format: 3 Points

Returns the correct value: 5 Points

-calculate_velocity: 10 points

Correct function header: 2 Points

Prints in the correct format: 3 Points

Correct response is calculated: 5 Points

-liquid_converter: 10 points

Correct function header: 2 Points

Prints in the correct format: 3 Points

Correct response is calculated: 5 Points

-calorie_counter: 15 points

Correct function header: 2 Points

Prints in the correct format: 3 Points

Correct response is calculated: 7 Points

-paycheck_computation: 20 points

Correct function header: 2 Points

Prints in the correct format: 3 Points

Returns correct value: 8 Points

-main: 5 points

Calls the correct function: 5 Points

Provided

The following file(s) have been provided to you. There are several, but you will only edit one of them:

    1. HW1.py

This is the file you will edit and implement. All instructions for what the methods should do are in the docstrings.

Deliverables

You must submit all of the following file(s). Please make sure the filename matches the filename(s) below. Be sure you receive the confirmation email from T-Square, and then download your uploaded files to a new folder and run them.

    1. HW1.py

    2. First_Last.jpg


Authors: Lucille Wang | Report Issues: lucillewang@gatech.edu