Issue #94: Created SG.py (This is a file that handles functionality for the Singapore locale)

[nathanielmiller23]

This issue came from here: #94

What I did:

• I implemented a file, SG.py to handle the functionality for Singaporean holidays to be used in holidata.
• For holidays occurring on the same day, I was simply able to use the link referred to by the issue creator: https://www.mom.gov.sg/employment-practices/public-holidays
• For holidays with variable dates, I hardcoded them, dating back to the year 2011, which is the earliest year for which holidata provides data. The hardcoded dates contain data up until the year 2026 and would likely need to be updated at a later date. From one of my sources:

A majority of the holidays celebrated in Singapore are based on different religious beliefs. Many of these holidays occur on different dates each year because they are based on different calendars and the lunar cycle. The Ministry of Manpower will release the official holiday dates towards the end of each year for the following year.

Christian holidays that use the lunar cycle are based off of the Gregorian calendar. Muslim holidays based off of the lunar cycle in Singapore are calculated by the Majlis Ugama Islam lunar visibility criteria. Hindu holidays are based off of the Hindu lunar calendar. If more than one holiday occurs on the same date because of lunar calculations, an additional holiday is given to replace it and to eliminate “bad luck.”

With this in mind, hard-coding certain holidays for the Singapore locale will likely be a necessity.

Sources:

• https://www.mom.gov.sg/employment-practices/public-holidays
• https://publicholidays.sg/

[lauft]

@nathanielmiller23 Thanks for your contribution. I left some comments to be addressed before merging. Also, please update the snapshot tests for this new locale.

[lauft]

Thanks for the update. Apart from the comments I made, could you also rebase your branch to the current HEAD?

[lauft]

I apologize for being a bit imprecise with my statement "For all other countries the legal sources are added as a comment".

What I meant was to use a docstring for this information, i.e. wrap in triple quotes and put it to the top.
In general, try to align the layout with the other country files.

[lauft]

As mentioned in the comment to shift_to_monday_if_weekend, use SmartDayArrow for all dates, i.e. do not use the datetime module at all. Also here, sorry for my imprecision when I just said "Use holidatas class SmartDayArrow..."

See other country files on how to this is done, e.g. the region file for Ceuta where a date map similar to those used by you here is defined, or the country file for Great Britain.

[lauft]

Those are the wrong test files... 😅 You need to add those for en_SG.

Add your locale to holidata/holidays/init.py, sorted alphabetically into the list, rerun pytest tests/test_holidata.py --update-snapshots to create the snapshots for SG, and add those (and only those). If any other tests are red or have to be modified, that's an error 😉

[lauft]

@nathanielmiller23 I have dropped the dependency to snapshottest in favor of syrupy; the latter seems better maintained and already supports Python 3.12.

This makes it mandatory to rebase your PR before adding the snapshot files for your locale.