Pyramid: Quick traversal example

main.py

from pyramid.httpexceptions import HTTPCreated, HTTPBadRequest
from pyramid.views import view_config

 
def includeme(config):
    config.set_root_factory(Root)
    config.scan()

    
class Root(object):
    children = {
        'tags': TagsCollection,
    }
    
    def __getitem__(self, key):
        self.children[key](key, self)
        

class TagsCollection(object):
    def __init__(self, name, parent):
        self.__name__ = name
        self.__parent__ = parent
 
    def create(self, params):
        try:
            name = params['tag_name']
        except KeyError:
            raise HTTPBadRequest('missing tag_name param')
        new_resource = TagResource(name, self)
        new_resource.create(params)
        return new_resource
  
    def __getitem__(self, name):
        return TagResource(name, self)
 
 
class TagResource(object):
 
    def __init__(self, name, parent):
        self.__name__ = name
        self.__parent__ = parent
    
    def create(self, params):
        # call model to create tag on db
        db.create_tag(self.__name__, params)
        return self
 
 
@view_config(context=TagsCollection, request_method='POST', renderer='json')
@view_config(context=TagResource, request_method='PUT', renderer='json')
def create_tag(context, request):
    new_resource = context.create(request.params)
    return HTTPCreated(location=request.resource_url(new_resource))
    

This still works ✨

Two changes needed: Root class must be defined after the classes referenced in children dict, and needs an init method with signature __init__(self, request).