handle type null example properly

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonClientCodegen.java

@@ -710,7 +710,7 @@ public class PythonClientCodegen extends DefaultCodegen implements CodegenConfig
         for (int i=0 ; i< indentation ; i++) indentation_string += "    ";
         String example = super.toExampleValue(schema);
 
-        if (ModelUtils.isNullType(schema) && null != example) {
+        if (ModelUtils.isNullType(schema)) {
             // The 'null' type is allowed in OAS 3.1 and above. It is not supported by OAS 3.0.x,
             // though this tooling supports it.
             return "None";