Delete other/date_to_weekday.py as a how-to-use, not an algorithm

[spazm]

Describe your change:

Fixes type annotations on other/date_to_weekday.

• strptime() returns a datetime, not a datetime.date.
• dynamic switch from int to str is fine in a dynamic language, but the type checker needs to be told it is expected.

Before

% git checkout master 
Switched to branch 'master'
Your branch is up to date with 'origin/master'.

(% mypy  date_to_weekday.py
date_to_weekday.py:19: error: Incompatible types in assignment (expression has type "str", variable has type "int")
date_to_weekday.py:21: error: Function "datetime.datetime.date" is not valid as a type
date_to_weekday.py:21: note: Perhaps you need "Callable[...]" or a callback protocol?
date_to_weekday.py:22: error: datetime.date? has no attribute "weekday"
Found 3 errors in 1 file (checked 1 source file)

After

% git checkout -
Switched to branch 'mypy-fix-other-date_to_weekday'
Your branch is up to date with 'origin/mypy-fix-other-date_to_weekday'.

% mypy  date_to_weekday.py
Success: no issues found in 1 source file

% mypy  --strict date_to_weekday.py
Success: no issues found in 1 source file

• 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}.

[spazm]

apologies: had to rebase my pr branches to fix my author email address.

[cclauss]

Instead of:

from typing import Union
year: Union[int, str]
# this repo has been moving to the new syntax by doing
from __future__ import annotations
year: int | str  # or year: [int | str]

However, I question the base logic of the year % 100 thing because not all years that are evenly divisible by 100 are the same year.

>>> [(i, datetime(i, 1, 1).weekday()) for i in range(200, 2200, 100)]
[ (200, 2),  (300, 0),  (400, 5),  (500, 4),
  (600, 2),  (700, 0),  (800, 5),  (900, 4),
 (1000, 2), (1100, 0), (1200, 5), (1300, 4),
 (1400, 2), (1500, 0), (1600, 5), (1700, 4),
 (1800, 2), (1900, 0), (2000, 5), (2100, 4)]

[spazm]

The algorithm was definitely flawed. I just wanted to add types :)

I've rewritten the algo, which boils it down to two calls to the standard lib. If we want to manually parse a string by splitting on /, that can be added back in.

[poyea]

Should we keep a full implementation here?

[cclauss]

My sense is that we should delete the entire file. This is a how-to-use the datetime module, not an algorithm.

[poyea]

And we already have https://github.com/TheAlgorithms/Python/blob/master/other/doomsday.py

[cclauss]

Thanks for your effort @spazm but this file has got to go.

[poyea]

@spazm In fact the test cases in b9fee14 can go into https://github.com/TheAlgorithms/Python/blob/master/other/doomsday.py. Feel free to open a new PR