def test_join_option_string_types():
a = symbol('a', 'var * {x: ?string}')
b = symbol('b', 'var * {x: string}')
c = symbol('c', 'var * {x: ?string}')
assert (join(a, b, 'x').dshape == join(b, a, 'x').dshape ==
dshape('var * {x: string}'))
assert (join(a, c, 'x').dshape == join(c, a, 'x').dshape ==
dshape('var * {x: ?string}'))
def test_join_on_single_column():
a = symbol('a', 'var * {x: int, y: int, z: int}')
b = symbol('b', 'var * {x: int, y: int, w: int}')
expr = join(a, b.x)
assert expr.on_right == 'x'
def test_join_suffixes():
a = symbol('a', 'var * {x: int, y: int}')
b = join(a, a, 'x', suffixes=('_l', '_r'))
assert isdistinct(b.fields)
assert len(b.fields) == 3
assert set(b.fields) == set(['x', 'y_l', 'y_r'])
def test_join_on_same_table():
a = symbol('a', 'var * {x: int, y: int}')
c = join(a, a, 'x')
assert isdistinct(c.fields)
assert len(c.fields) == 3
def test_join_on_same_columns():
a = symbol('a', 'var * {x: int, y: int, z: int}')
b = symbol('b', 'var * {x: int, y: int, w: int}')
c = join(a, b, 'x')
assert isdistinct(c.fields)
assert len(c.fields) == 5
assert 'y_left' in c.fields
assert 'y_right' in c.fields
def test_join_exceptions():
"""
exception raised for mismatched schema;
exception raised for no shared fields
"""
a = symbol('a', 'var * {x: int}')
b = symbol('b', 'var * {x: string}')
with pytest.raises(TypeError) as excinfo:
join(a, b, 'x')
assert "Schemata of joining columns do not match," in str(excinfo.value)
assert "x=int32 and x=string" in str(excinfo.value)
b = symbol('b', 'var * {z: int}')
with pytest.raises(ValueError) as excinfo:
join(a, b)
assert "No shared columns between a and b" in str(excinfo.value)
b = symbol('b', 'var * {x: int}')
with pytest.raises(ValueError) as excinfo:
join(a, b, how='inner_')
assert "Got: inner_" in str(excinfo.value)
def test_raise_error_if_join_on_no_columns():
a = symbol('a', 'var * {x: int}')
b = symbol('b', 'var * {y: int}')
assert raises(ValueError, lambda: join(a, b))
def test_join_option_types():
a = symbol('a', 'var * {x: ?int}')
b = symbol('b', 'var * {x: int}')
assert join(a, b, 'x').dshape == dshape('var * {x: int}')
assert join(b, a, 'x').dshape == dshape('var * {x: int}')
def test_join_type_promotion_option():
a = symbol('a', 'var * {x: ?int32}')
b = symbol('b', 'var * {x: int64}')
assert join(a, b, 'x').dshape == dshape('var * {x: int64}')
def test_join_mismatched_schema():
a = symbol('a', 'var * {x: int}')
b = symbol('b', 'var * {x: string}')
with pytest.raises(TypeError):
join(a, b, 'x')
def test_join_option_types_outer():
a = symbol('a', 'var * {x: ?int}')
b = symbol('b', 'var * {x: int}')
assert (join(a, b, 'x', how='outer').dshape == join(
b, a, 'x', how='outer').dshape == dshape('var * {x: ?int}'))
