def test_generate_range_on_edges():
offset = to_offset("AS")
start = datetime(2000, 1, 1)
end = datetime(2100, 1, 1)
res = generate_range(start, end, offset)
exp = [datetime(y, 1, 1) for y in range(start.year, end.year + 1)]
assert list(res) == exp
def test_generate_range(start, end):
offset = to_offset("AS")
start = start
end = end
res = generate_range(start, end, offset)
exp = [datetime(y, 1, 1) for y in range(start.year, end.year + 2)]
assert list(res) == exp
def test_month_start():
offset = to_offset("MS")
dt = datetime(2001, 2, 12)
res = offset.rollback(dt)
assert res.year == 2001
assert res.month == 2
assert res.day == 1
res = offset.rollforward(dt)
assert res.year == 2001
assert res.month == 3
assert res.day == 1
def test_invalid_offsets(offset_rule):
with pytest.raises(ValueError):
to_offset(offset_rule)