Returning Index instead of boolean in knuth_morris_pratt (kmp) function, making it compatible with str.find().

[HetarthJain]

Describe your change:

Returning the index of first occurrence of a match in knuth_morris_pratt algorithm. The return type is converted from boolean to int. The function name parameters are aligned to Python naming conventions.
Fixes#9077

• 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 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 Returning index instead of boolean when knuth_morris_pratt matches. #9077".

[rohan472000]

Kindly tick the checkboxes while raising PR, see contributing guidelines beforehand.

[HetarthJain]

Kindly tick the checkboxes while raising PR, see contributing guidelines beforehand.

I have ticked the appropriate checkboxes.

[HetarthJain]

Please review the Pull request

[rohan472000]

#9079 is also doing the same, check that first.

[rohan472000]

Also keep your PR title descriptive, remove 9077 and add kmp in it, as viewers can understand easily.

[rohan472000]

Meanwhile, @HetarthJain you can look into that doctest which is failing in #9079.

[HetarthJain]

Meanwhile, @HetarthJain you can look into that doctest which is failing in #9079.

I have used the doctest in the commit itself, it has passed. Please review it.

[rohan472000]

Add these doctests there in kmp() function:

>>> kmp = "knuth_morris_pratt"
>>> knuth_morris_pratt(kmp, "kn") == kmp.find("kn")
True
>>> knuth_morris_pratt(kmp, "h_m") == kmp.find("h_m")
True
>>> knuth_morris_pratt(kmp, "rr") == kmp.find("rr")
True
>>> knuth_morris_pratt(kmp, "tt") == kmp.find("tt")
True
>>> knuth_morris_pratt(kmp, "not there") == kmp.find("not there")
True
>>> all(knuth_morris_pratt(kmp, s) == kmp.find(s) for s in ( "kn", "h_m", "rr", "tt", "not there" ))
True

Run: python3 -m doctest -v main.py to run doctest only (replace main.py with your filename),I checked it is passing.

[rohan472000]

@cclauss kindly have a look at this PR, your doctest for knuth_morris_pratt is getting passed here.

[cclauss]

I had to add doctests because this PR had none.

https://docs.python.org/3/library/doctest.html

[HetarthJain]

Thanks @cclauss and @rohan472000 for your guidance in my first PR