feat(api): move from .case() to .cases() (#9096)

Author: NickCrews

docs/_freeze/posts/ci-analysis/index/execute-results/html.json

@@ -332,7 +332,7 @@ quartodoc:
             - name: ifelse
               dynamic: true
               signature_name: full
-            - name: case
+            - name: cases
               dynamic: true
               signature_name: full
 

docs/_quarto.yml

@@ -203,13 +203,11 @@ Let's also give them some names that'll look nice on our plots.
 stats = stats.mutate(
     raw_improvements=_.has_poetry.cast("int") + _.has_team.cast("int")
 ).mutate(
-    improvements=(
-        _.raw_improvements.case()
-        .when(0, "None")
-        .when(1, "Poetry")
-        .when(2, "Poetry + Team Plan")
-        .else_("NA")
-        .end()
+    improvements=_.raw_improvements.cases(
+        (0, "None"),
+        (1, "Poetry"),
+        (2, "Poetry + Team Plan"),
+        else_="NA",
     ),
     team_plan=ibis.ifelse(_.raw_improvements > 1, "Poetry + Team Plan", "None"),
 )

docs/posts/ci-analysis/index.qmd

@@ -466,11 +466,11 @@ semantics:
 case = (
     t.one.cast("timestamp")
     .year()
-    .case()
-    .when(2015, "This year")
-    .when(2014, "Last year")
-    .else_("Earlier")
-    .end()
+    .cases(
+        (2015, "This year"),
+        (2014, "Last year"),
+        else_="Earlier",
+    )
 )
 
 expr = t.mutate(year_group=case)
@@ -489,18 +489,16 @@ CASE
 END
 ```
 
-To do this, use `ibis.case`:
+To do this, use `ibis.cases`:
 
 ```{python}
-case = (
-    ibis.case()
-    .when(t.two < 0, t.three * 2)
-    .when(t.two > 1, t.three)
-    .else_(t.two)
-    .end()
+cases = ibis.cases(
+    (t.two < 0, t.three * 2),
+    (t.two > 1, t.three),
+    else_=t.two,
 )
 
-expr = t.mutate(cond_value=case)
+expr = t.mutate(cond_value=cases)
 ibis.to_sql(expr)
 ```
 

docs/tutorials/ibis-for-sql-users.qmd

@@ -201,22 +201,18 @@ def test_ifelse(alltypes, df, op, pandas_op):
 
 def test_simple_case(con, alltypes, assert_sql):
     t = alltypes
-    expr = (
-        t.string_col.case().when("foo", "bar").when("baz", "qux").else_("default").end()
-    )
+    expr = t.string_col.cases(("foo", "bar"), ("baz", "qux"), else_="default")
 
     assert_sql(expr)
     assert len(con.execute(expr))
 
 
 def test_search_case(con, alltypes, assert_sql):
     t = alltypes
-    expr = (
-        ibis.case()
-        .when(t.float_col > 0, t.int_col * 2)
-        .when(t.float_col < 0, t.int_col)
-        .else_(0)
-        .end()
+    expr = ibis.cases(
+        (t.float_col > 0, t.int_col * 2),
+        (t.float_col < 0, t.int_col),
+        else_=0,
     )
 
     assert_sql(expr)

ibis/backends/clickhouse/tests/test_operators.py

@@ -14,13 +14,13 @@ def table(mockcon):
 
 @pytest.fixture
 def simple_case(table):
-    return table.g.case().when("foo", "bar").when("baz", "qux").else_("default").end()
+    return table.g.cases(("foo", "bar"), ("baz", "qux"), else_="default")
 
 
 @pytest.fixture
 def search_case(table):
     t = table
-    return ibis.case().when(t.f > 0, t.d * 2).when(t.c < 0, t.a * 2).end()
+    return ibis.cases((t.f > 0, t.d * 2), (t.c < 0, t.a * 2))
 
 
 @pytest.fixture

ibis/backends/impala/tests/test_case_exprs.py

@@ -8,7 +8,6 @@
 import pytest
 from pytest import param
 
-import ibis
 import ibis.expr.datatypes as dt
 from ibis import udf
 
@@ -122,36 +121,23 @@ def predict_price(
         df.columns = ["CARAT_SCALED", "CUT_ENCODED", "COLOR_ENCODED", "CLARITY_ENCODED"]
         return model.predict(df)
 
-    def cases(value, mapping):
-        """This should really be a top-level function or method."""
-        expr = ibis.case()
-        for k, v in mapping.items():
-            expr = expr.when(value == k, v)
-        return expr.end()
-
     diamonds = con.tables.DIAMONDS
     expr = diamonds.mutate(
         predicted_price=predict_price(
             (_.carat - _.carat.mean()) / _.carat.std(),
-            cases(
-                _.cut,
-                {
-                    c: i
-                    for i, c in enumerate(
-                        ("Fair", "Good", "Very Good", "Premium", "Ideal"), start=1
-                    )
-                },
+            _.cut.cases(
+                (c, i)
+                for i, c in enumerate(
+                    ("Fair", "Good", "Very Good", "Premium", "Ideal"), start=1
+                )
             ),
-            cases(_.color, {c: i for i, c in enumerate("DEFGHIJ", start=1)}),
-            cases(
-                _.clarity,
-                {
-                    c: i
-                    for i, c in enumerate(
-                        ("I1", "IF", "SI1", "SI2", "VS1", "VS2", "VVS1", "VVS2"),
-                        start=1,
-                    )
-                },
+            _.color.cases((c, i) for i, c in enumerate("DEFGHIJ", start=1)),
+            _.clarity.cases(
+                (c, i)
+                for i, c in enumerate(
+                    ("I1", "IF", "SI1", "SI2", "VS1", "VS2", "VVS1", "VVS2"),
+                    start=1,
+                )
             ),
         )
     )

ibis/backends/snowflake/tests/test_udf.py

@@ -159,13 +159,13 @@ def difference(con):
 @pytest.fixture(scope="module")
 def simple_case(con):
     t = con.table("alltypes")
-    return t.g.case().when("foo", "bar").when("baz", "qux").else_("default").end()
+    return t.g.cases(("foo", "bar"), ("baz", "qux"), else_="default")
 
 
 @pytest.fixture(scope="module")
 def search_case(con):
     t = con.table("alltypes")
-    return ibis.case().when(t.f > 0, t.d * 2).when(t.c < 0, t.a * 2).end()
+    return ibis.cases((t.f > 0, t.d * 2), (t.c < 0, t.a * 2))
 
 
 @pytest.fixture(scope="module")

ibis/backends/tests/sql/conftest.py

@@ -22,18 +22,14 @@
 lit2 = ibis.literal("bar")
 
 result = alltypes.select(
-    alltypes.g.case()
-    .when(lit, lit2)
-    .when(lit1, ibis.literal("qux"))
-    .else_(ibis.literal("default"))
-    .end()
-    .name("col1"),
-    ibis.case()
-    .when((alltypes.g == lit), lit2)
-    .when((alltypes.g == lit1), alltypes.g)
-    .else_(ibis.literal(None))
-    .end()
-    .name("col2"),
+    alltypes.g.cases(
+        (lit, lit2), (lit1, ibis.literal("qux")), else_=ibis.literal("default")
+    ).name("col1"),
+    ibis.cases(
+        ((alltypes.g == lit), lit2),
+        ((alltypes.g == lit1), alltypes.g),
+        else_=ibis.literal(None),
+    ).name("col2"),
     alltypes.a,
     alltypes.b,
     alltypes.c,

ibis/backends/tests/sql/snapshots/test_select_sql/test_case_in_projection/decompiled.py

@@ -461,8 +461,8 @@ def test_bool_bool(snapshot):
 
 def test_case_in_projection(alltypes, snapshot):
     t = alltypes
-    expr = t.g.case().when("foo", "bar").when("baz", "qux").else_("default").end()
-    expr2 = ibis.case().when(t.g == "foo", "bar").when(t.g == "baz", t.g).end()
+    expr = t.g.cases(("foo", "bar"), ("baz", "qux"), else_=("default"))
+    expr2 = ibis.cases((t.g == "foo", "bar"), (t.g == "baz", t.g))
     expr = t.select(expr.name("col1"), expr2.name("col2"), t)
 
     snapshot.assert_match(to_sql(expr), "out.sql")

ibis/backends/tests/sql/test_select_sql.py

@@ -611,7 +611,7 @@ def test_first_last(alltypes, method, filtered, include_null):
     # To sanely test this we create a column that is a mix of nulls and a
     # single value (or a single value after filtering is applied).
     if filtered:
-        new = alltypes.int_col.cases([(3, 30), (4, 40)])
+        new = alltypes.int_col.cases((3, 30), (4, 40))
         where = _.int_col == 3
     else:
         new = (alltypes.int_col == 3).ifelse(30, None)
@@ -738,7 +738,7 @@ def test_arbitrary(alltypes, filtered):
     # _something_ we create a column that is a mix of nulls and a single value
     # (or a single value after filtering is applied).
     if filtered:
-        new = alltypes.int_col.cases([(3, 30), (4, 40)])
+        new = alltypes.int_col.cases((3, 30), (4, 40))
         where = _.int_col == 3
     else:
         new = (alltypes.int_col == 3).ifelse(30, None)
@@ -1571,9 +1571,7 @@ def collect_udf(v):
 
 def test_binds_are_cast(alltypes):
     expr = alltypes.aggregate(
-        high_line_count=(
-            alltypes.string_col.case().when("1-URGENT", 1).else_(0).end().sum()
-        )
+        high_line_count=alltypes.string_col.cases(("1-URGENT", 1), else_=0).sum()
     )
 
     expr.execute()
@@ -1616,7 +1614,7 @@ def test_agg_name_in_output_column(alltypes):
 def test_grouped_case(backend, con):
     table = ibis.memtable({"key": [1, 1, 2, 2], "value": [10, 30, 20, 40]})
 
-    case_expr = ibis.case().when(table.value < 25, table.value).else_(ibis.null()).end()
+    case_expr = ibis.cases((table.value < 25, table.value), else_=ibis.null())
 
     expr = (
         table.group_by(k="key")

ibis/backends/tests/test_aggregation.py

@@ -3,6 +3,7 @@
 from collections import Counter
 
 import pytest
+from pytest import param
 
 import ibis
 
@@ -62,18 +63,13 @@ def test_substitute(backend):
 @pytest.mark.parametrize(
     "inp, exp",
     [
-        pytest.param(
-            lambda: ibis.literal(1)
-            .case()
-            .when(1, "one")
-            .when(2, "two")
-            .else_("other")
-            .end(),
+        param(
+            lambda: ibis.literal(1).cases((1, "one"), (2, "two"), else_="other"),
             "one",
             id="one_kwarg",
         ),
-        pytest.param(
-            lambda: ibis.literal(5).case().when(1, "one").when(2, "two").end(),
+        param(
+            lambda: ibis.literal(5).cases((1, "one"), (2, "two")),
             None,
             id="fallthrough",
         ),
@@ -94,13 +90,8 @@ def test_value_cases_column(batting):
     np = pytest.importorskip("numpy")
 
     df = batting.to_pandas()
-    expr = (
-        batting.RBI.case()
-        .when(5, "five")
-        .when(4, "four")
-        .when(3, "three")
-        .else_("could be good?")
-        .end()
+    expr = batting.RBI.cases(
+        (5, "five"), (4, "four"), (3, "three"), else_="could be good?"
     )
     result = expr.execute()
     expected = np.select(
@@ -113,7 +104,7 @@ def test_value_cases_column(batting):
 
 
 def test_ibis_cases_scalar():
-    expr = ibis.literal(5).case().when(5, "five").when(4, "four").end()
+    expr = ibis.literal(5).cases((5, "five"), (4, "four"))
     result = expr.execute()
     assert result == "five"
 
@@ -128,12 +119,8 @@ def test_ibis_cases_column(batting):
 
     t = batting
     df = batting.to_pandas()
-    expr = (
-        ibis.case()
-        .when(t.RBI < 5, "really bad team")
-        .when(t.teamID == "PH1", "ph1 team")
-        .else_(t.teamID)
-        .end()
+    expr = ibis.cases(
+        (t.RBI < 5, "really bad team"), (t.teamID == "PH1", "ph1 team"), else_=t.teamID
     )
     result = expr.execute()
     expected = np.select(
@@ -148,5 +135,45 @@ def test_ibis_cases_column(batting):
 @pytest.mark.notimpl("clickhouse", reason="special case this and returns 'oops'")
 def test_value_cases_null(con):
     """CASE x WHEN NULL never gets hit"""
-    e = ibis.literal(5).nullif(5).case().when(None, "oops").else_("expected").end()
+    e = ibis.literal(5).nullif(5).cases((None, "oops"), else_="expected")
     assert con.execute(e) == "expected"
+
+
+@pytest.mark.parametrize(
+    ("example", "expected"),
+    [
+        param(lambda: ibis.case().when(True, "yes").end(), "yes", id="top-level-true"),
+        param(lambda: ibis.case().when(False, "yes").end(), None, id="top-level-false"),
+        param(
+            lambda: ibis.case().when(False, "yes").else_("no").end(),
+            "no",
+            id="top-level-false-value",
+        ),
+        param(
+            lambda: ibis.literal("a").case().when("a", "yes").end(),
+            "yes",
+            id="method-true",
+        ),
+        param(
+            lambda: ibis.literal("a").case().when("b", "yes").end(),
+            None,
+            id="method-false",
+        ),
+        param(
+            lambda: ibis.literal("a").case().when("b", "yes").else_("no").end(),
+            "no",
+            id="method-false-value",
+        ),
+    ],
+)
+def test_ibis_case_still_works(con, example, expected):
+    # test that the soft-deprecated .case() method still works
+    # https://github.com/ibis-project/ibis/pull/9096
+    pd = pytest.importorskip("pandas")
+
+    with pytest.warns(FutureWarning):
+        expr = example()
+
+    result = con.execute(expr)
+
+    assert (expected is None and pd.isna(result)) or result == expected