Increase code coverage for dijkstra algorithm

[r055a]

Describe your change:

Ref #9943

Add doctests to dijkstra_algorithm.py to improve code coverage
Bug fixed where required to execute and pass doctests
Moved method declaration comments to doc strings for methods doc strings are added to for the doctests

Code coverage improved from 16% to 85% (or 100% when not including the main block)

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Add or change doctests? -- Note: Please avoid changing both code and tests in a single pull request.
• 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 include at least one URL that points to Wikipedia or another similar explanation.
• If this pull request resolves one or more open issues then the description above includes the issue number(s) with a closing keyword: "Fixes #ISSUE-NUMBER".

[cclauss]

In the commit message above, what does the second checked bullet say?

[r055a]

In the commit message above, what does the second checked bullet say?

Thank you @cclauss for the feedback. Are you referring to the PR comment? I may have misinterpreted. I made changes to some variable names for readability. I have removed the tick.

[cclauss]

Please open a new pull request and copy in ONLY the doctests from this pull request. Once that new pull request is merged, we can come back to the code changes in this pull request.

[r055a]

Please open a new pull request and copy in ONLY the doctests from this pull request. Once that new pull request is merged, we can come back to the code changes in this pull request.

Hi @cclauss I have removed code changes in this PR so that only doctests remain with exception for a bug fix in the min_heapify method. Considering method doc strings are used for the doctests, I have also moved method description comments into these.

[r055a]

Hi @cclauss is there any possibility of this PR being merged soon as I would prefer it to be so before continuing with code changes in a new PR

[cclauss]

Please make PriorityQueue a https://docs.python.org/3/library/dataclasses.html