feat: move from .case() to .cases()

Fixes #7280

docs/posts/ci-analysis/index.qmd

@@ -203,14 +203,12 @@ 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.where(_.raw_improvements > 1, "Poetry + Team Plan", "None"),
 )
 stats

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

@@ -473,11 +473,11 @@ 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)
@@ -496,18 +496,16 @@ 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)
 ```
 

ibis/backends/clickhouse/tests/test_operators.py

@@ -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/dask/tests/test_operations.py

@@ -773,64 +773,6 @@ def q_fun(x, quantile):
     tm.assert_series_equal(result, expected, check_index=False)
 
 
-def test_searched_case_scalar(client):
-    expr = ibis.case().when(True, 1).when(False, 2).end()
-    result = client.execute(expr)
-    expected = np.int8(1)
-    assert result == expected
-
-
-def test_searched_case_column(batting, batting_pandas_df):
-    t = batting
-    df = batting_pandas_df
-    expr = (
-        ibis.case()
-        .when(t.RBI < 5, "really bad team")
-        .when(t.teamID == "PH1", "ph1 team")
-        .else_(t.teamID)
-        .end()
-    )
-    result = expr.execute()
-    expected = pd.Series(
-        np.select(
-            [df.RBI < 5, df.teamID == "PH1"],
-            ["really bad team", "ph1 team"],
-            df.teamID,
-        )
-    )
-    tm.assert_series_equal(result, expected, check_names=False)
-
-
-def test_simple_case_scalar(client):
-    x = ibis.literal(2)
-    expr = x.case().when(2, x - 1).when(3, x + 1).when(4, x + 2).end()
-    result = client.execute(expr)
-    expected = np.int8(1)
-    assert result == expected
-
-
-def test_simple_case_column(batting, batting_pandas_df):
-    t = batting
-    df = batting_pandas_df
-    expr = (
-        t.RBI.case()
-        .when(5, "five")
-        .when(4, "four")
-        .when(3, "three")
-        .else_("could be good?")
-        .end()
-    )
-    result = expr.execute()
-    expected = pd.Series(
-        np.select(
-            [df.RBI == 5, df.RBI == 4, df.RBI == 3],
-            ["five", "four", "three"],
-            "could be good?",
-        )
-    )
-    tm.assert_series_equal(result, expected, check_names=False)
-
-
 def test_table_distinct(t, df):
     expr = t[["dup_strings"]].distinct()
     result = expr.compile()

ibis/backends/impala/tests/test_case_exprs.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/pandas/executor.py

@@ -167,6 +167,8 @@ def visit(cls, op: ops.IsNan, arg):
     def visit(
         cls, op: ops.SearchedCase | ops.SimpleCase, cases, results, default, base=None
     ):
+        if not cases:
+            return default
         if base is not None:
             cases = tuple(base == case for case in cases)
         cases, _ = cls.asframe(cases, concat=False)

ibis/backends/pandas/tests/test_operations.py

@@ -683,73 +683,9 @@ def test_summary_non_numeric(batting, batting_df):
     assert dict(result.iloc[0]) == expected
 
 
-def test_searched_case_scalar(client):
-    expr = ibis.case().when(True, 1).when(False, 2).end()
-    result = client.execute(expr)
-    expected = np.int8(1)
-    assert result == expected
-
-
-def test_searched_case_column(batting, batting_df):
-    t = batting
-    df = batting_df
-    expr = (
-        ibis.case()
-        .when(t.RBI < 5, "really bad team")
-        .when(t.teamID == "PH1", "ph1 team")
-        .else_(t.teamID)
-        .end()
-    )
-    result = expr.execute()
-    expected = pd.Series(
-        np.select(
-            [df.RBI < 5, df.teamID == "PH1"],
-            ["really bad team", "ph1 team"],
-            df.teamID,
-        )
-    )
-    tm.assert_series_equal(result, expected)
-
-
-def test_simple_case_scalar(client):
-    x = ibis.literal(2)
-    expr = x.case().when(2, x - 1).when(3, x + 1).when(4, x + 2).end()
-    result = client.execute(expr)
-    expected = np.int8(1)
-    assert result == expected
-
-
-def test_simple_case_column(batting, batting_df):
-    t = batting
-    df = batting_df
-    expr = (
-        t.RBI.case()
-        .when(5, "five")
-        .when(4, "four")
-        .when(3, "three")
-        .else_("could be good?")
-        .end()
-    )
-    result = expr.execute()
-    expected = pd.Series(
-        np.select(
-            [df.RBI == 5, df.RBI == 4, df.RBI == 3],
-            ["five", "four", "three"],
-            "could be good?",
-        )
-    )
-    tm.assert_series_equal(result, expected)
-
-
 def test_non_range_index():
     def do_replace(col):
-        return col.cases(
-            (
-                (1, "one"),
-                (2, "two"),
-            ),
-            default="unk",
-        )
+        return col.cases((1, "one"), (2, "two"), else_="unk")
 
     df = pd.DataFrame(
         {

ibis/backends/snowflake/tests/test_udf.py

@@ -8,7 +8,6 @@
 import pytest
 from pytest import param
 
-import ibis
 import ibis.expr.datatypes as dt
 from ibis import udf
 
@@ -115,36 +114,23 @@ 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/sql/compiler.py

@@ -935,6 +935,8 @@ def visit_VarianceStandardDevCovariance(self, op, *, how, where, **kw):
     )
 
     def visit_SimpleCase(self, op, *, base=None, cases, results, default):
+        if not cases:
+            return default
         return sge.Case(
             this=base, ifs=list(map(self.if_, cases, results)), default=default
         )

ibis/backends/tests/sql/conftest.py

@@ -164,13 +164,13 @@ 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/snapshots/test_select_sql/test_case_in_projection/decompiled.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).cast("string"))
-    .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).cast("string"),
+    ).name("col2"),
     alltypes.a,
     alltypes.b,
     alltypes.c,

ibis/backends/tests/sql/test_select_sql.py

@@ -397,8 +397,8 @@ 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[expr.name("col1"), expr2.name("col2"), t]
 
     snapshot.assert_match(to_sql(expr), "out.sql")