These exercises focuses on Python loops and functions. The functions start out trivial and ramp up in difficulty. The main goals of these exercises are:
- Gain familiarity with writing and calling functions that take arguments and return results
- Decompose a problem into the various parts of a for-loop
- Familiarize with VS Code built-in test suite
You are provided a starter file named main.py
, which contains an empty definition of each function. Complete each function so that it prints the required result to the console. Most of these build on each other, which means that you'll need to complete them in order.
Complete the function named add
which takes two integers and returns their sum.
- The function should handle negative values
- Use of built-in operator
+
is allowed - Display the result of calling add(2, 4), which should be 6
Complete the function named multiply
which takes two integers and returns their product.
- Use of built-in operator
-
and theabs()
function is allowed - Use of all other built-in arithmetic operators or functions is not allowed (e.g.
*
,**
,+
,/
,//
,sum()
, etc.) - Use a for-loop which calls the
add()
function you wrote earlier - This function must correctly handle negative values
- Display the result of calling
multiply(6, -8)
, which should be -48
Write a function named power
that takes two arguments (x and n) and returns the the result of raising x to the nth power.
- Use of built-in arithmetic operators or functions is not allowed
- Use the functions you wrote in the previous exercises to write this function
- The function should correctly handle negative values of x (but not y)
- Display the result of calling
power(2, 8)
, which should be 256
Another word for this is exponentiation. In the above example, we arrive at 256 by multiplying 2 by itself 8 times:
2 * 2 * 2 * 2 * 2 * 2 * 2 * 2 = 256
If we had called power(3, 4), we'd want to multiply 3 by itself 4 times:
3 * 3 * 3 * 3 = 81
See this Wikipedia article for more details on exponentiation.
Write a function named factorial
that takes a single argument and returns the factorial of that argument.
-
You may not use built-in arithmetic operators or functions
-
Use the functions you wrote in the previous exercises to write this function
-
Display the result of calling
factorial(4)
, which should be 244 * 3 * 2 * 1 = 24
Write a function named fibonacci
that takes an integer n
and returns the nth Fibonacci number. For the purposes of this assignment, we'll be using the classical series, which starts counting at 0, rather than the combinatorial series, which starts counting at 1.
-
You may not use built-in arithmetic operators or functions
-
Use the functions you wrote in the previous exercises to write this function
-
Display the result of calling
fibonacci(8)
, which should be 210 1 1 2 3 5 8 13 [21] ...
The number in brackets is the 8th fibonacci number, if we start counting terms from 0 instead of 1.
The answer to most of these will look similar. They will typically involve:
- declaring a variable to keep track of a final result
- writing a for loop to consistently modify the result
- returning the result
If you struggle for more than 5 minutes, ask for help! This is an exercise in critical thinking, not torture.
This assignment comes bundled with a "Test Suite" โ a set of tests to validate each function you write. VS Code has a built-in test runner framework. Read this article about how to enable test discovery in VS Code. You will need to know how to run similar tests in future assignments.
- Fork this repository into your own personal GitHub account.
- Clone your own repo to your local development machine.
- Create a separate branch named
dev
and checkout the branch. - Commit your changes, then
git push
the branch back to your own GitHub account. - From your own GitHub repo, create a pull request (PR) from your
dev
branch back to your own master. - Copy/Paste the URL link to your PR as your assignment submission.
- Your grader will post code review comments inline within your pull request in your GitHub account. Be sure to respond to any comments and make requested changes. RESUBMIT a new link to your PR after making changes. This is the code review iteration cycle.