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File Searching

File Searching

Project Goals

This engineering effort invites you to combine what you learned about the basics of Python programming to implement a useful program that can search for a word in a file. As you enhance your technical skills, you will program with tools such as VS Code and a terminal window and the Python programming language and the Poetry package manager.

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" button in the file-search-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!

Expected Output

This project invites you to implement a file searching program called search. The search program takes as input a word (e.g., "proactive") and determines whether or not it is in the text of a file provided on the input. For instance, if the file called input/proactive.txt contains inside of the text on the main page of this web site, then searching for the word proactive with the command poetry run search --word ethical --dir input --file proactive.txt yields:

😃 Searching through the file called input/proactive.txt!

Was the word "ethical" found in the file input/proactive.txt? Yes

When you search for a word that does not appear inside of the input file with a command like poetry run search --word conundrum --dir input --file proactive.txt then the program will produce the following output:

😃 Searching through the file called input/proactive.txt!

Was the word "conundrum" found in the file input/proactive.txt? No

Once your program is working correctly, you should also try to use it when specify a file that is not available on your computer! For instance, if you run it with the command poetry run search --word proactive --dir input --file notfound.txt then it will not perform a search and instead produce the following output:

😃 Searching through the file called input/notfound.txt!

🤷 input/notfound.txt was not a valid file

Don't forget that if you want to run the search program you must use your terminal window to first go into the GitHub repository containing this project and then go into the search directory that contains the project's source code. Finally, remember that before running the program you must run poetry install to add the dependencies.

Adding Functionality

If you study the file search/search/ you will see that it has many TODO markers that designate the parts of the program that you need to implement before search will produce correct output. If you run the provided test suite with the command poetry run task test you will see that it produces output like the following:

================================== ERRORS ==================================
__________________ ERROR collecting tests/ ___________________
tests/ in <module>
    from search import main
search/ in <module>
E   NameError: name 'cli' is not defined
========================= short test summary info ==========================
ERROR tests/ - NameError: name 'cli' is not defined
!!!!!!!!!!!!!!!!!!!!!!!! stopping after 1 failures !!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!
============================= 1 error in 0.11s =============================

Alternatively, running the program with a command like poetry run search --word ethical --dir input --file proactive.txt will produce the following output:

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/home/gkapfham/.pyenv/versions/3.9.2/lib/python3.9/importlib/", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1030, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
  File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 680, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 790, in exec_module
  File "<frozen importlib._bootstrap>", line 228, in _call_with_frames_removed
NameError: name 'cli' is not defined

This output suggests that the cli variable was not correctly declared! After declaring the cli variable in the appropriate fashion, following the relevant instructions in the description of the technical skills, you should find the other TODO markers and correctly resolve them. For instance, you can add this function to the file:

def confirm_valid_file(file: Path) -> bool:
    """Confirm that the provided file is a valid path."""
    # determine if the file is not None and if it is a file
    if file is not None:
        # the file is valid
        if file.is_file():
            return True
    # the file was either none or not valid
    return False

Line 1 of the above source code segment contains the signature for the confirm_valid_file function, showing that it takes as input a file variable that is of type Path and returns a bool to indicate whether or not the file is valid. If the conditional logic on lines 4 and 6 confirms that the file variable is both not equal to None and is, in fact, a file, then the function returns True. Otherwise, line 9 of confirm_valid_file returns False to indicate that the provided file is not valid.

In addition to confirm_valid_file, you must completely implement these functions:

  • def human_readable_boolean(answer: bool) -> str
  • def word_search(text: str, word: str) -> bool
  • def word(word: str = typer.Option(None), dir: Path = typer.Option(None), file: Path = typer.Option(None)) -> None

Running Checks

If you study the source code in the pyproject.toml file you will see that it includes the following section that specifies different executable tasks like lint. If you are in the search directory that contains the pyproject.toml file and the poetry.lock file, the tasks in this section make it easy to run commands like poetry run task lint to automatically run all of the linters designed to check the Python source code in your program and its test suite. You can also use the command poetry run task black to confirm that your source code adheres to the industry-standard format defined by the black tool. If it does not adhere to the standard then you can run the command poetry run black search tests and it will automatically reformat the source code.

Along with running tasks like poetry run task lint, you can leverage the relevant instructions in the technical skills to run the command gatorgrade --config config/gatorgrade.yml to check your work. If your work meets the baseline requirements and adheres to the best practices that proactive programmers adopt you will see that all the checks pass when you run gatorgrade. You can study the config/gatorgrade.yml file in your repository to learn how the GatorGrade program runs GatorGrader to automatically check your program and technical writing.

If your program has all of the anticipated functionality, you can run the command poetry run task test and see that the test suite produces output like this:

collected 5 items

tests/ .....

Don't forget that when you commit source code or technical writing to your GitHub repository for this project, it will trigger the run of a GitHub Actions workflow. If you are a student at Allegheny College, then running this workflow consumes build minutes for the course's organization! As such, you should only commit to your repository once you have made substantive changes to your project and you are ready to confirm its correctness. Before you commit to your repository, you can should run checks on your own computer by running gatorgrade --config config/gatorgrade.yml.

Project Reflection

Once you have finished both of the previous technical tasks, you can use a text editor to answer all of the questions in the writing/ file. For instance, you should provide the output of the Python program in a fenced code block, explain the meaning of the Python source code segments that you implemented, and answer all of the other questions about your experiences in completing this project.


To ensure that you master the technical and professional skills introduced as part of this project you need to participate in deliberate practice that "requires both a clear performance goal and immediate informative feedback".1 After reflecting on the challenges that you faced and identifying areas for improvement, make a list of SMART goals that will enable you to more effectively put a specific technical skill into practice, follow your plan, and continually work to improve.2 You can learn more about how to best reflect on your experiences and improve before starting your next project by reviewing the technical skills that a proactive programmer should master!

Project Assessment

Since this project is an engineering effort, it is aligned with the evaluating and creating 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 every aspect of the project's specification.


Before you finish all of the required deliverables required by this project is worth pausing to remember that the instructor will give advance feedback to any learner who requests it through GitHub and Discord at least 24 hours before the project's due date! Seriously, did you catch that? This policy means that you can have a thorough understanding of ways to improve your project before its final assessment! To learn more about this opportunity, please read the assessment strategy for this site.

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.

  1. See Merriam-Webster for the definition of Teaching Tech Together for more details about how to effectively learn technical skills. What practical steps can you take to best ensure that you can master the technical skills of a proactive programmer? 

  2. See the article called How to write SMART goals for an overview of how to create SMART goals that are specific, measurable, achievable, relevant, and time-bound. In your view, what are the benefits of ensuring that your goals fit into the SMART paradigm? 

Updated: 2023-03-17   Created: 2021-08-10
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