Impreratively creating sequence of mapping schemas in Colander and Deform - deform

Question

I am constructing a page where user can leave reviews for any number of products in Colander and Deform. I have grasped all the required elements, but I have still some issues of connecting the dots. Specifically, how I can imperatively (dynamically) create a sequence of N form items and then bind data for them?
This is my attempt for this far:
reviews =[
{
"product": "Shampoo",
"comment": ""
"rating": 3,
},
{
"product": "Soap",
"comment": "",
"rating:" 3,
},
]
rating = colander.Schema()
rating.add(colander.SchemaNode(colander.Int(), name="rating", missing=colander.null, validator=colander.Range(1, 5)))
rating.add(colander.SchemaNode(colander.String(), name="comment", validator=colander.Length(max=4096), missing=""))
ratings = colander.SequenceSchema(name="ratings", default=reviews, children=[rating])
# schema.add(colander.SchemaNode(colander.Sequence(), rating, name="ratings", default=reviews))
schema = CSRFSchema()
schema.add(ratings)
form = deform.Form(schema)
if request.method == "POST":
controls = request.POST.items()
try:
captured = form.validate(controls)
except deform.ValidationFailure as e:
return {'form': e.render()}
else:
rendered_form = form.render()
return locals()
But this results to error:
ValueError: Prototype for <deform.field.Field object at 4576735072 (schemanode 'ratings')> has no name

Answer 1

Ok - figured it out. The innermost SchemaNode() must be named. One must use colander.SchemaNode(colander.Sequence()) to map out sequence of items.
reviews =[
{
"product": "Shampoo",
"comment": "",
"rating": 3,
},
{
"product": "Soap",
"comment": "",
"rating": 3,
},
]
rating = colander.Schema(name="single_rating")
rating.add(colander.SchemaNode(colander.Int(), name="rating", missing=colander.null, validator=colander.Range(1, 5)))
rating.add(colander.SchemaNode(colander.String(), name="comment", validator=colander.Length(max=4096), missing=""))
ratings = colander.SchemaNode(colander.Sequence(), rating, name="ratings", default=reviews)
# schema.add(colander.SchemaNode(colander.Sequence(), rating, name="ratings", default=reviews))
schema = CSRFSchema()
schema.add(ratings)
form = deform.Form(schema)
if request.method == "POST":
controls = request.POST.items()
try:
captured = form.validate(controls)
except deform.ValidationFailure as e:
return {'form': e.render()}
else:
rendered_form = form.render()
return locals()