fix(python): self as property name leads to assignment error (#1330)

When a property with the name `self` exists in a class, it leads to
a runtime error. This slugifies the conventional `self` parameter
as needed to avoid this problem without compromising on the
developer experience.

---

By submitting this pull request, I confirm that my contribution is made under the terms of the [Apache 2.0 license].

[Apache 2.0 license]: https://www.apache.org/licenses/LICENSE-2.0

packages/@jsii/python-runtime/tests/test_compliance.py

@@ -73,6 +73,10 @@
     AnonymousImplementationProvider,
     UpcasingReflectable,
 )
+from jsii_calc.python_self import (
+    ClassWithSelf,
+    ClassWithSelfKwarg,
+)
 from scope.jsii_calc_lib import IFriendly, EnumFromScopedModule, Number
 from scope.jsii_calc_lib.submodule import IReflectable, ReflectableEntry
 
@@ -1182,3 +1186,13 @@ def test_load_submodules():
     from jsii_calc.submodule import nested_submodule
     import jsii_calc.submodule
 
+
+def test_parameter_named_self_ClassWithSelf():
+    subject = ClassWithSelf('Howdy!')
+    assert subject.self == 'Howdy!'
+    assert subject.method(1337) == '1337'
+
+
+def test_parameter_named_self_ClassWithSelfKwarg():
+    subject = ClassWithSelfKwarg(self='Howdy!')
+    assert subject.props.self == 'Howdy!'

packages/jsii-calc/lib/compliance.ts

@@ -960,6 +960,31 @@ export class PythonReservedWords {
     public yield() {}
 }
 
+// "self" is technically not a keyword in Python. It's the conventional name of
+// the "this instance" reference. We can slugify this to our heart's content,
+// without much impact on the developer experience - but it needs to happen!
+export namespace PythonSelf {
+    export class ClassWithSelf {
+        public constructor(public readonly self: string) { }
+
+        public method(self: number): string {
+            return self.toString();
+        }
+    }
+
+    export class ClassWithSelfKwarg {
+        public constructor(public readonly props: StructWithSelf) { }
+    }
+
+    export interface StructWithSelf {
+        readonly self: string;
+    }
+
+    export interface IInterfaceWithSelf {
+        method(self: number): string;
+    }
+}
+
 export interface UnionProperties {
     readonly foo?: string | number;
     readonly bar: AllTypes | string | number;