fix type issue (remove .first() function)

[alifeee]

this was not caught by #1296's CI because type-checking was not yet enabled in the workflow.

This is the main change:

- value = str(data.first())
+ try:
+     value = str(data[0][0])
+ except IndexError:
+     value = str(None)

...which replaces the call to ValueRange.first() with its implementation

gspread/gspread/worksheet.py

Lines 140 to 148 in 6944c1f

	def first(self, default: Optional[str] = None) -> Optional[str]:
	"""Returns the value of a first cell in a range.
	If the range is empty, return the default value.
	"""
	try:
	return self[0][0]
	except IndexError:
	return default

The error was because before #1296, get returned a ValueRange. After #1296, it returns ValueRange | List[List[Any]], so the type checking complained that .first() was not a method on List[List[Any]]. I'm not sure how to solve this issue by typinig, which is why I did what I did here.

Why is .first() needed as a function anyway? It is hardly used. I propose that we don't need it (but we should keep it, and just not use it internally).

[msramalho]

FYI the changes made the default go from None to "None" which is, to the best of my knowledge, not described in the migration to 6.0.0. Are there more such breaking changes related to dropping first() or how the data is read and returned in general?

eg impact: bellingcat/auto-archiver#124

[alifeee]

FYI the changes made the default go from None to "None" which is, to the best of my knowledge, not described in the migration to 6.0.0. Are there more such breaking changes related to dropping first() or how the data is read and returned in general?

This is simply a mistake on our part. There is no reason to change the default behaviour, a change that we didn't see with this PR.

I'll change it back to the previous argument and make a minor release.

[msramalho]

Oh that's brilliant, thanks.