def test_join():
df_left = DataFrame(
{"a": ["a", "b", "a", "z"], "b": [1, 2, 3, 4], "c": [6, 5, 4, 3],}
)
df_right = DataFrame(
{"a": ["b", "c", "b", "a"], "k": [0, 3, 9, 6], "c": [1, 0, 2, 1],}
)
joined = df_left.join(df_right, left_on="a", right_on="a").sort("a")
assert joined["b"].series_equal(Series("", [1, 3, 2, 2]))
joined = df_left.join(df_right, left_on="a", right_on="a", how="left").sort("a")
assert joined["c_right"].is_null().sum() == 1
assert joined["b"].series_equal(Series("", [1, 3, 2, 2, 4]))
joined = df_left.join(df_right, left_on="a", right_on="a", how="outer").sort("a")
assert joined["c_right"].null_count() == 1
assert joined["c"].null_count() == 2
assert joined["b"].null_count() == 2
def test_join():
df_left = DataFrame({
"a": ["a", "b", "a", "z"],
"b": [1, 2, 3, 4],
"c": [6, 5, 4, 3],
})
df_right = DataFrame({
"a": ["b", "c", "b", "a"],
"k": [0, 3, 9, 6],
"c": [1, 0, 2, 1],
})
joined = df_left.join(df_right, left_on="a", right_on="a").sort("a")
assert joined["b"].series_equal(Series("", [1, 3, 2, 2]))
joined = df_left.join(df_right, left_on="a", right_on="a",
how="left").sort("a")
assert joined["c_right"].is_null().sum() == 1
assert joined["b"].series_equal(Series("", [1, 3, 2, 2, 4]))
joined = df_left.join(df_right, left_on="a", right_on="a",
how="outer").sort("a")
assert joined["c_right"].null_count() == 1
assert joined["c"].null_count() == 2
assert joined["b"].null_count() == 2
df_a = DataFrame({"a": [1, 2, 1, 1], "b": ["a", "b", "c", "c"]})
df_b = DataFrame({
"foo": [1, 1, 1],
"bar": ["a", "c", "c"],
"ham": ["let", "var", "const"]
})
# just check if join on multiple columns runs
df_a.join(df_b, left_on=["a", "b"], right_on=["foo", "bar"])
eager_join = df_a.join(df_b, left_on="a", right_on="foo")
lazy_join = df_a.lazy().join(df_b.lazy(), left_on="a",
right_on="foo").collect()
assert lazy_join.shape == eager_join.shape
