Merge pull request #9385 from Tishj/python_string_annotations

[Python] Support PEP 563

tools/pythonpkg/src/python_udf.cpp

@@ -279,9 +279,20 @@ struct PythonUDFData {
 		}
 	}
 
-	void AnalyzeSignature(const py::object &udf) {
+	py::object GetSignature(const py::object &udf) {
+		const int32_t PYTHON_3_10_HEX = 0x030a00f0;
+		auto python_version = PY_VERSION_HEX;
+
 		auto signature_func = py::module_::import("inspect").attr("signature");
-		auto signature = signature_func(udf);
+		if (python_version >= PYTHON_3_10_HEX) {
+			return signature_func(udf, py::arg("eval_str") = true);
+		} else {
+			return signature_func(udf);
+		}
+	}
+
+	void AnalyzeSignature(const py::object &udf) {
+		auto signature = GetSignature(udf);
 		auto sig_params = signature.attr("parameters");
 		auto return_annotation = signature.attr("return_annotation");
 		if (!py::none().is(return_annotation)) {

tools/pythonpkg/tests/fast/test_string_annotation.py

@@ -0,0 +1,53 @@
+import duckdb
+import pytest
+import sys
+from typing import Union
+
+
+def make_annotated_function(type: str):
+    def test_base():
+        return None
+
+    import types
+
+    test_function = types.FunctionType(
+        test_base.__code__, test_base.__globals__, test_base.__name__, test_base.__defaults__, test_base.__closure__
+    )
+    # Add the 'type' string as return_annotation
+    test_function.__annotations__ = {'return': type}
+    return test_function
+
+
+def python_version_lower_than_3_10():
+    import sys
+
+    if sys.version_info[0] < 3:
+        return True
+    if sys.version_info[1] < 10:
+        return True
+    return False
+
+
+class TestStringAnnotation(object):
+    @pytest.mark.skipif(
+        python_version_lower_than_3_10(), reason="inspect.signature(eval_str=True) only supported since 3.10 and higher"
+    )
+    @pytest.mark.parametrize(
+        ['input', 'expected'],
+        [
+            ('str', 'VARCHAR'),
+            ('list[str]', 'VARCHAR[]'),
+            ('dict[str, str]', 'MAP(VARCHAR, VARCHAR)'),
+            ('dict[Union[str, bool], str]', 'MAP(UNION(u1 VARCHAR, u2 BOOLEAN), VARCHAR)'),
+        ],
+    )
+    def test_string_annotations(self, duckdb_cursor, input, expected):
+        from inspect import signature
+
+        func = make_annotated_function(input)
+        sig = signature(func)
+        assert sig.return_annotation.__class__ == str
+
+        duckdb_cursor.create_function("foo", func)
+        rel = duckdb_cursor.sql("select foo()")
+        assert rel.types == [expected]