data_structures/linked_list: Adding __str__() function #3960

[arif599]

Describe your change:

Added a str() function to the Linked List class that will print the contents in the Linked List with arrows that point to the next value

see: #3960

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Documentation change?

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms have a URL in its comments that points to Wikipedia or other similar explanation.
• If this pull request resolves one or more open issues then the commit message contains Fixes: #{$ISSUE_NO}.

[arif599]

I'm not really sure what went wrong during the build check.

[amaank404]

Your doctest failed, please verify it

[arif599]

Thanks for bringing that up. I've never used doctests in python before so I'll do some more research. Based upon looking at other Pull Requests, I thought it was just a comment that shows others how to use it but I didn't know it also gets executed.

[amaank404]

Will fix any doctest errors, make the output better to look at without any extra arrow at the end

also a spelling error iteam -> item

[arif599]

Will fix any doctest errors, make the output better to look at without any extra arrow at the end

also a spelling error iteam -> item

Thank you for catching that spelling mistake. I really like the format of the output, I committed the changes you added.

[dhruvmanila]

If possible, can you add type hints for other functions/parameters as well? Thanks if you do, otherwise after this small change the PR is good to go.

[arif599]

Yeah definitely, I'll include type hinting and also add comments to describe some of the functionality. It's midnight for me, so I will have it done by tomorrow morning.

[amaank404]

Great, Also your doctests were failing because of the whitespace in that line which was required but trimmed by pre commit

[amaank404]

try this solution every time pre-commit fails:

• pip install pre-commit
• pre-commit run -a (It might show you it failed but it actually did not)
• Commit the changes and push them into your fork

[arif599]

try this solution every time pre-commit fails:

* `pip install pre-commit`

* `pre-commit run -a` (It might show you it failed but it actually did not)

* Commit the changes and push them into your fork

Thanks for letting me know! I have done what you suggested. I'll commit again.

[dhruvmanila]

pre-commit is a hook you install in your local git directory. Once it is installed, it will run automatically every time you commit your changes, but this is only for the local directory.

If you've downloaded pre-commit locally, then go to the root of your Python repository copy and run pre-commit install. That's it! Now, you don't have to worry about the pre-commit checks ever failing.

[dhruvmanila]

@xcodz-dot If you give instructions to users about installing pre-commit, then please tell them to do pre-commit install instead of pre-commit run -a. This will save you and the user a ton of time and energy.

[dhruvmanila]

LGTM!

[arif599]

Seriously thank you guys for helping and guiding me. I'm a little new to this but I'll continue to learn and make more meaningful contributions along the way!

[amaank404]

@xcodz-dot If you give instructions to users about installing pre-commit, then please tell them to do pre-commit install instead of pre-commit run -a. This will save you and the user a ton of time and energy.

I will sure do that, i am just going to add that to contributing.md and will make a PR quickly