Homework 7 [Extra Credit] – Functions and Modules

CMPSC 101 
Introduction to Programming in Python 
Homework 7 [Extra Credit] – Functions and Modules

Instructions: Write Python scripts (.py files) to solve the following problems. Output screenshots should also be
submitted. Use variables where necessary and give meaningful names to variables. All script files should have a
comment block at the top, and also provide comments alongside your code. Upload a .pdf/.docx file containing your
solutions along with your .py files.
Problem 1. Implement your own ‘mymath’ module. [60 points]
In this exercise, you are going to create and use your own math module ‘mymath’, which supports
six functions – add, subtract, multiply, divide, isPrime and factorial.
Your mymath.py file should have the definitions of the following six functions:
(i) add() –
Formal parameters: num1, num2
Return value: Sum of num1 and num2
(ii) subtract() –
Formal parameters: num1, num2
Return value: Difference of num1 and num2
(iii) multiply() –
Formal parameters: num1, num2
Return value: Product of num1 and num2
(iv) divide() –
Formal parameters: num1, num2
Return value: Division of num1 and num2
(v) isPrime() –
Formal parameter: num
Return value (Boolean): True if num is prime, False otherwise
[Your code should evaluate correctly for all non-negative integers]
(vi) factorial() –
Formal parameter: num
Return value: Factorial value of num
[Your code should evaluate correctly for all non-negative integers]
Now that you have implemented your module, it is time to test if it works correctly. Create a new
python script testmymath.py. In this script do the following:
(i) Import the module you just created.
(ii) Input two numbers from the user and save them in variables x and y.
(iii) Call add() with x and y as arguments (actual parameters) and save the returned
value in variable resAdd. Print the value of resAdd.
(iv) Call subtract() with x and y as arguments and save the returned value in variable
resSub. Print the value of resSub.
CMPSC 101 Instructor: Dr. Mahfuza Farooque
Introduction to Programming in Python Fall 2016
(v) Call multiply() with x and y as arguments and save the returned value in variable
resMul. Print the value of resMul.
(vi) Call divide() with x and y as arguments and save the returned value in variable
resDiv. Print the value of resDiv.
(vii) Call isPrime() with x as argument and save the returned value in variable resPri.
Print the value of resPri.
(viii) Call factorial() with y as argument and save the returned value in variable
resFac. Print the value of resFac.
Note that you need to use module_name.function_name format to call your functions. You
should run the test script multiple times with different values to ensure that the functions are
working properly.
Sample output of testtmymath.py:
Enter 1st number: 11
Enter 2nd number: 6
Sum = 17
Difference = 5
Product = 66
Division = 1.8333
11 is Prime
6 Factorial = 720
Files to be submitted:
1. Module: mymath.py
2. Test script: testmymath.py
3. Output screenshots
CMPSC 101 Instructor: Dr. Mahfuza Farooque
Introduction to Programming in Python Fall 2016
Problem 2. Write a python script fibonacci.py to compute the nth number in the Fibonacci
sequence (1, 1, 2, 3, 5, 8, 13, 21, …), where n is any positive integer. You have to do the following
in your script: [40 points]
(i) Define a function called fibonacci() that has one formal parameter n, and returns
the nth number in the Fibonacci sequence.
(ii) Write code that ask the user to enter a number and save it in variable num.
(iii) Call fibonacci() with num as argument and save the result in variable f. Print the
value of f.
Sample output I of fibonacci.py:
Enter a number: 5
Fibonacci = 5
Sample output II of fibonacci.py:
Enter a number: 2
Fibonacci = 1
Files to be submitted:
1. Script: fibonacci.py
2. Output screenshots