__bool__ method on Results

[simonw]

Wrote this code today: https://github.com/simonw/datasette-public/blob/1401bfae50e71c1dfd2bfb6954f2e86d5a7ab21b/datasette_public/__init__.py#L41

    results = await db.execute(
        "select 1 from _public_tables where table_name = ?", [table_name]
    )
    if len(results):
        return True

Would be nice if I could use if results there instead.

[simonw]

Code can go here:

datasette/datasette/database.py

Lines 511 to 515 in b6ba117

	def __iter__(self):
	return iter(self.rows)
	def __len__(self):
	return len(self.rows)

[simonw]

Turns out this already works - __bool__ falls back on __len__: https://docs.python.org/3/reference/datamodel.html#object.__bool__

When this method is not defined, __len__() is called, if it is defined, and the object is considered true if its result is nonzero.

I'll add a test to demonstrate this.