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Mode Calculation

Mode Calculation

Project Goals

This assignment invites you to run and observe one Python program called perform-mode-calculation. Instead of using the Poetry tool for managing dependencies and packaging these programs, which the technical skills advise as a best practice, this program is a script, without any dependencies on other Python packages, that you can run through the Python interpreter. The main reason that you can run the perform-mode-calculation as a script is because it does not have any external package dependencies, instead only using packages that are a part of the Python language. As you continue to practice a different way to run a Python program, this project invites you to explore how to (i) import the Counter module from the collections package, (ii) implement a function called calculate_mode that can find at most one mode inside of a list of numbers, and (iii) call the calculate_mode function and display the values in the tuple that it produces.

Project Access

If you are a student enrolled in a Computer Science class at Allegheny College, you can access this assignment by clicking the link provided to you in Discord. Once you click this link it will create a GitHub repository that you can clone to your computer by following the general-purpose instructions in the description of the technical skills. Specifically, you will need to use the git clone command to download the project from GitHub to your computer. Now you are ready to add source code and documentation to the project!


If you are an emerging proactive programmer who is not enrolled in a Computer Science class at Allegheny College, you can still work on this assignment! To get started, you should click the "Use this template" icon in the mode-calculation-starter GitHub repository and create your own version of this project's source code. After creating your GitHub repository, you can follow all of the other steps!

Code Survey

If you change into the source/ directory of your GitHub repository, you will see a Python program called Your goal for this project is to find and fix the defects in the function with the signature def calculate_mode(numbers: List[int]) -> Tuple[int, int]:. Specifically, this function signature indicates that the calculate_mode function takes as input a list of integer values and returns a tuple of two integers (i.e., an ordered pair) where the first value is the number that is the mode and the second value is the number of times that the mode appeared. To be clear, the calculate_mode function should find the mode of a list of numbers, or the number that appears most frequently in the list. When you run the command python after correcting the program's defects, it should produce the following output when it looks for a mode in the scores = [7, 8, 9, 2, 10, 9, 9, 9].

The mode of the list of numbers is 9
The mode of the list of was found 4 times!

It is worth noting that the calculate_mode function will only work correctly when it is provided with a list that contains a single value for the mode. If there are multiple values for the mode (i.e., the list scores = [7, 8, 7, 7, 9, 2, 10, 9, 9, 9] has both the number 7 and the number 9 as a mode) then it will not return both of them. How would you need to change the function's computation and the type of data that it returns in order to ensure that can return all modes that are evident in the input list? Finally, don't forget that it is only possible for the program to run correctly if it contains the import statements that make the classes for the type annotations available! This means that you need to have both from typing import List and from typing import Tuple at the top of the Since the source code in the Doing Math with Python book uses the Counter module, the script also needs the statement from collections import Counter.

Running Checks

Since this project does not use Poetry to manage project dependencies and virtual environments, it does not support the use of commands like poetry run task test. However, you can leverage the relevant instructions in the technical skills to enter into a Docker container and run the command gradle grade to check your work. If gradle grade shows that all checks pass, you will know that you made progress towards correctly implementing and writing about this project's program. You are also encouraged to implement your own test cases for the script to ensure that it is working correctly! This might involve creating different inputs to the function under test, calling the calculate_mode function, and then adding a statement to check that the function returned the correct ordered pair as its output.


Did you know that GatorGrade and GatorGrader are open-source Python programs implemented by many proactive programmers? If you finish this source code survey and have extra time, please brainstorm some new features that you think these two tools should have, explain your idea by raising an issue in the relevant project's GitHub repository, and take the first step towards implementing and testing your idea. If the maintainers of these tools accept your new feature then you will have helped to improve the experience of other people who use GatorGrade and GatorGrader!

Project Reflection

Once you have finished all of the previous technical tasks, you can use a text editor to answer all of the questions in the writing/ file. Since this is a source code survey, you should provide output from running each of the provided Python programs on your own laptop and then explain how the program's source code produced that output. A specific goal for this project is for you to improve and document the source code of a function that indexes a tuple in order to swap its contents.

Project Assessment

Since this project is source code survey, it is aligned with the remembering and understanding levels of Bloom's taxonomy. You can learn more about how a proactive programming expert will assess your work by examining the assessment strategy. From the start to the end of this project you may make an unlimited number of reattempts at submitting source code and technical writing that meet the project's specification.

Seeking Assistance

Emerging proactive programmers who have questions about this project are invited to ask them in either the GitHub discussions forum or the Proactive Programmers Discord server. Before you ask your question, please read the advice concerning how to best participate in the Proactive Programmers community. If you find a mistake in this project, please describe it and propose a solution by creating an issue in the GitHub Issue Tracker.

Updated: 2023-04-14   Created: 2021-09-16
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