diff --git a/pkg/gen/filters/filterpy/filters.go b/pkg/gen/filters/filterpy/filters.go
index 0e5b29c2..4dbe218a 100644
--- a/pkg/gen/filters/filterpy/filters.go
+++ b/pkg/gen/filters/filterpy/filters.go
@@ -15,4 +15,5 @@ func PopulateFuncMap(fm template.FuncMap) {
 	fm["pyVars"] = pyVars
 	fm["pyType"] = pyType
 	fm["pyExtern"] = pyExtern
+	fm["pyTestValue"] = pyTestValue
 }
diff --git a/pkg/gen/filters/filterpy/py_testvalue.go b/pkg/gen/filters/filterpy/py_testvalue.go
new file mode 100644
index 00000000..6d52c893
--- /dev/null
+++ b/pkg/gen/filters/filterpy/py_testvalue.go
@@ -0,0 +1,93 @@
+package filterpy
+
+import (
+	"fmt"
+
+	"github.com/apigear-io/cli/pkg/gen/filters/common"
+	"github.com/apigear-io/cli/pkg/model"
+)
+
+// ToTestValueString returns the test value string for a given schema.
+// We intentionally ignore arrays in order to return the test value of the inner type.
+func ToTestValueString(prefix string, schema *model.Schema) (string, error) {
+	if schema == nil {
+		return "xxx", fmt.Errorf("pyTestValue schema is nil")
+	}
+	if schema.Module == nil {
+		return "xxx", fmt.Errorf("pyTestValue schema module is nil")
+	}
+	var text string
+	switch schema.KindType {
+	case model.TypeString:
+		text = "\"xyz\""
+	case model.TypeInt, model.TypeInt32, model.TypeInt64:
+		text = "1"
+	case model.TypeFloat, model.TypeFloat32, model.TypeFloat64:
+		text = "1.1"
+	case model.TypeBool:
+		text = "True"
+	case model.TypeVoid:
+		return ToDefaultString(schema, prefix)
+	case model.TypeEnum:
+		e_local := schema.LookupEnum("", schema.Type)
+		e_imported := schema.LookupEnum(schema.Import, schema.Type)
+		if e_local == nil && e_imported == nil {
+			return "xxx", fmt.Errorf("pyTestValue enum not found: %s", schema.Dump())
+		}
+		// if enum is local it is found both as e_local and e_imported
+		name := common.CamelTitleCase(e_imported.Name)
+		member := common.SnakeUpperCase(e_imported.Members[0].Name)
+		if len(e_imported.Members) > 1 {
+			member = common.SnakeUpperCase(e_imported.Members[1].Name)
+		}
+		if e_local == nil {
+			prefix = fmt.Sprintf("%s.api.", e_imported.Module.Name)
+		}
+		text = fmt.Sprintf("%s%s.%s", prefix, name, member)
+	case model.TypeStruct:
+		s_local := schema.LookupStruct("", schema.Type)
+		s_imported := schema.LookupStruct(schema.Import, schema.Type)
+		if s_local == nil && s_imported == nil {
+			return "xxx", fmt.Errorf("pyTestValue struct not found: %s", schema.Dump())
+		}
+		// if struct is local it is found both as s_local and s_imported
+		ident := common.CamelTitleCase(s_imported.Name)
+		if s_local == nil {
+			prefix = fmt.Sprintf("%s.api.", s_imported.Module.Name)
+		}
+		text = fmt.Sprintf("%s%s()", prefix, ident)
+	case model.TypeExtern:
+		xe := parsePyExtern(schema)
+		if xe.Default != "" {
+			text = xe.Default
+		} else {
+			py_module := ""
+			if xe.Import != "" {
+				py_module = fmt.Sprintf("%s.", xe.Import)
+			}
+			text = fmt.Sprintf("%s%s()", py_module, xe.Name)
+		}
+	case model.TypeInterface:
+		i_local := schema.LookupInterface("", schema.Type)
+		i_imported := schema.LookupInterface(schema.Import, schema.Type)
+		if i_local == nil && i_imported == nil {
+			return "xxx", fmt.Errorf("pyTestValue interface not found: %s", schema.Dump())
+		}
+		// if interface is local it is found both as s_local and s_imported
+		ident := common.CamelTitleCase(i_imported.Name)
+		if i_local == nil {
+			prefix = fmt.Sprintf("%s.api.", i_imported.Module.Name)
+		}
+		text = fmt.Sprintf("%s%s()", prefix, ident)
+	default:
+		return "xxx", fmt.Errorf("pyTestValue unknown schema %s", schema.Dump())
+	}
+	return text, nil
+}
+
+func pyTestValue(prefix string, node *model.TypedNode) (string, error) {
+	if node == nil {
+		return "xxx", fmt.Errorf("pyTestValue node is nil")
+	}
+	return ToTestValueString(prefix, &node.Schema)
+}
diff --git a/pkg/gen/filters/filterpy/py_testvalue_test.go b/pkg/gen/filters/filterpy/py_testvalue_test.go
new file mode 100644
index 00000000..d86b488e
--- /dev/null
+++ b/pkg/gen/filters/filterpy/py_testvalue_test.go
@@ -0,0 +1,140 @@
+package filterpy
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// test with all the types
+// properties, operation params, operation return, signal params, struct fields
+func TestTestValueFromIdl(t *testing.T) {
+	t.Parallel()
+	syss := loadTestSystems(t)
+	var propTests = []struct {
+		mn string
+		in string
+		pn string
+		rt string
+	}{
+		{"test", "Test1", "propVoid", "None"},
+		{"test", "Test1", "propBool", "True"},
+		{"test", "Test1", "propInt", "1"},
+		{"test", "Test1", "propInt32", "1"},
+		{"test", "Test1", "propInt64", "1"},
+		{"test", "Test1", "propFloat", "1.1"},
+		{"test", "Test1", "propFloat32", "1.1"},
+		{"test", "Test1", "propFloat64", "1.1"},
+		{"test", "Test1", "propString", "\"xyz\""},
+		{"test", "Test1", "propBoolArray", "True"}, // all the array types return value intentionally, it may be put into empty array
+		{"test", "Test1", "propIntArray", "1"},
+		{"test", "Test1", "propInt32Array", "1"},
+		{"test", "Test1", "propInt64Array", "1"},
+		{"test", "Test1", "propFloatArray", "1.1"},
+		{"test", "Test1", "propFloat32Array", "1.1"},
+		{"test", "Test1", "propFloat64Array", "1.1"},
+		{"test", "Test1", "propStringArray", "\"xyz\""},
+	}
+	for _, sys := range syss {
+		for _, tt := range propTests {
+			t.Run(tt.pn, func(t *testing.T) {
+				prop := sys.LookupProperty(tt.mn, tt.in, tt.pn)
+				assert.NotNil(t, prop)
+				r, err := pyTestValue("", prop)
+				assert.NoError(t, err)
+				assert.Equal(t, tt.rt, r)
+			})
+		}
+	}
+}
+
+func TestTestValueSymbolsFromIdl(t *testing.T) {
+	t.Parallel()
+	syss := loadTestSystems(t)
+	var propTests = []struct {
+		mn string
+		in string
+		pn string
+		rt string
+	}{
+		{"test", "Test2", "propEnum", "Enum1.NOT_DEFAULT"},
+		{"test", "Test2", "propStruct", "Struct1()"},
+		{"test", "Test2", "propInterface", "Interface1()"},
+		{"test", "Test2", "propEnumArray", "Enum1.NOT_DEFAULT"},
+		{"test", "Test2", "propStructArray", "Struct1()"},
+		{"test", "Test2", "propInterfaceArray", "Interface1()"},
+	}
+	for _, sys := range syss {
+		for _, tt := range propTests {
+			t.Run(tt.pn, func(t *testing.T) {
+				prop := sys.LookupProperty(tt.mn, tt.in, tt.pn)
+				assert.NotNil(t, prop)
+				r, err := pyTestValue("", prop)
+				assert.NoError(t, err)
+				assert.Equal(t, tt.rt, r)
+			})
+		}
+	}
+}
+
+func TestTestValueWithErrors(t *testing.T) {
+	t.Parallel()
+	s, err := pyTestValue("", nil)
+	assert.Error(t, err)
+	assert.Equal(t, "xxx", s)
+}
+
+func TestTestValueReturnsExternDefault(t *testing.T) {
+	syss := loadExternSystems(t)
+	var propTests = []struct {
+		mn string
+		in string
+		pn string
+		rt string
+	}{
+		{"demo", "Iface1", "prop1", "XType1()"},
+		{"demo", "Iface1", "prop2", "XType2()"},
+		{"demo", "Iface1", "prop3", "XType3A()"},
+	}
+	for _, sys := range syss {
+		for _, tt := range propTests {
+			t.Run(tt.pn, func(t *testing.T) {
+				prop := sys.LookupProperty(tt.mn, tt.in, tt.pn)
+				assert.NotNil(t, prop)
+				r, err := pyTestValue("", prop)
+				assert.NoError(t, err)
+				assert.Equal(t, tt.rt, r)
+			})
+		}
+	}
+}
+
+func TestTestValueReturnsDefaultExterns(t *testing.T) {
+	t.Parallel()
+	table := []struct {
+		module_name    string
+		interface_name string
+		operation_name string
+		result         string
+	}{
+		{"test_apigear_next", "Iface1", "prop1", "XType1()"},
+		{"test_apigear_next", "Iface1", "prop2", "demo.x.XType2()"},
+		{"test_apigear_next", "Iface1", "prop3", "demo.x.createXType3A()"},
+		{"test_apigear_next", "Iface1", "propList", "demo.x.createXType3A()"},
+		{"test_apigear_next", "Iface1", "propImportedEnum", "test.api.Enum1.NOT_DEFAULT"},
+		{"test_apigear_next", "Iface1", "propImportedStruct", "test.api.Struct1()"},
+	}
+	syss := loadExternSystemsYAML(t)
+	prefix := "my_prefix::"
+	for _, sys := range syss {
+		for _, tt := range table {
+			t.Run(tt.operation_name, func(t *testing.T) {
+				prop := sys.LookupProperty(tt.module_name, tt.interface_name, tt.operation_name)
+				assert.NotNil(t, prop)
+				r, err := pyTestValue(prefix, prop)
+				assert.NoError(t, err)
+				assert.Equal(t, tt.result, r)
+			})
+		}
+	}
+}
diff --git a/pkg/gen/filters/testdata/test.module.yaml b/pkg/gen/filters/testdata/test.module.yaml
index 7c7f53d0..e4a3ad1e 100644
--- a/pkg/gen/filters/testdata/test.module.yaml
+++ b/pkg/gen/filters/testdata/test.module.yaml
@@ -319,9 +319,11 @@ enums:
   - name: Enum1
     members:
       - name: Default
+      - name: NotDefault
   - name: EnumLowerNames
     members:
       - name: firstValue
+      - name: secondValue
 
 structs:
   - name: Struct1