Colander 2023
```python # Python code using Colander for form validation import colander from pyramid.view import view_config class MySchema(colander.MappingSchema): username = colander.SchemaNode(colander.String()) email = colander.SchemaNode(colander.String(), validator=colander.Email()) @view_config(renderer='your_template.mako') def my_view(request): schema = MySchema() form = deform.Form(schema, buttons=('submit',)) if 'submit' in request.POST: try: # validate the submitted data data = form.validate(request.POST.items()) # process the validated data # ... except deform.ValidationFailure as e: return {'form': e.render()} return {'form': form.render()}```html ${form}