def test_lean_by_with_summary():
assert lean_projection(by(t.x, total=t.y.sum()))._child.isidentical(
t[['x', 'y']], )
tt = t[['x', 'y']]
result = lean_projection(by(t.x, a=t.y.sum(), b=t.z.sum())[['x', 'a']])
expected = Projection(
By(Field(tt, 'x'), summary(a=sum(Field(tt, 'y')))),
('x', 'a'),
)
assert result.isidentical(expected)
def test_indexing():
t = symbol('t', 'var * {name: string, amount: int, id: int}')
assert t[['amount', 'id']] == projection(t, ['amount', 'id'])
assert t['amount'].isidentical(Field(t, 'amount'))