I'm trying to check if a model exists in the PredictionEnginePool by calling predictionEnginePool.GetModel(modelName: "ModelA") but I get an exception saying the model is not in the Dictionary even though I pass in the correct model name specified during creation.
Is this the right way to look for a model or is there a better way?
CEO, I don't think there's currently a way to check if a model has been loaded or not. I recommend submitting an issue as a suggestion to the ML.NET repo. https://github.com/dotnet/machinelearning
Related
An Setting belongs to an Office. Each time a Setting is updated, I make a new entry in the database, passing the old Setting to active=False and the new Setting to active=true. So each office has only one active setting at a time (i'm doing this because I wan't to keep track of old settings).
Now what I need is a way to access this setting via the Office object.
At the moment I am accessing it with the backwards relation office.setting_set.
I'm using Django-Rest-Framework so I need a field that is serializable.
In my serializer, I call: office.setting_set. In regular django I could probably do office.setting_set.filter(active=True) but I can't do so in a serializer...
The ideal would be a custom model field that I would call something like:
office.active_setting
Any idea how I can achieve this?
You can use model methods for this. The method would likely be something similar to the following:
def active_setting(self):
return self.setting_set.get(active=True)
I have a model with many fields. I need to run a code only when two specific fields are changed. I know I can modify my model's save() method but I don't know how to check which fields are changed in my ModelForm.
Sorry because i cant give you any code snippet since i am not very experienced in Django, but i would go for getting a signal when a change is done through a controler class listening on the models and hearing for changes. Hope i might helped a bit.
Good luck
Django-model-utils has something called a FieldTracker that does exactly this. Just instantiate it in your model and tell it to track the specific fields you're looking for. Then you can use the has_changed method to test if a given field has changed since the last save.
This package has some other great utilities as well, I really recommend looking through the docs.
You could try django-dirtyfields.
I'm porting a project from Rails to Django with a legacy database. In Rails I had a polymorphic association that allowed me to add a footnote to any row in the database. I'm trying to implement the same thing in the Django app. I found the documentation on Generic Relations and it looks perfect. Unfortunately, I first need to create new fields in my legacy database to hold the ContentType id for the relevant models. I only used the polymorphic association with 2 tables, so all I need are those two corresponding ids from the Django app, but I can't seem to find the appropriate command for looking up a ContentType id in Django.
Any suggestions are most welcome. I tried searching through previous questions but couldn't seem to find what I am looking for. Thank you very much for you time and help.
from the docs
you can do:
>>> b = Bookmark.objects.get(url='https://www.djangoproject.com/')
>>> bookmark_type = ContentType.objects.get_for_model(b)
>>> TaggedItem.objects.filter(content_type__pk=bookmark_type.id,
... object_id=b.id)
so just instantiate an instance of your model and then do ContentType.objects.get_for_model(<instance>).id
I think there's a way to pass just the model name, too... let me know if that would work better and I'll try to find it; I've used it in the past.
You can also get ContentType ID without creating an instance, which is more efficient if you don't have and don't need an instance but just want to get ContentType ID by model name.
ContentType.objects.get(model='bookmark').id
Notes : if the name of your model is upper case, please use lower case to search. For example: model = 'bookmark' rather than 'Bookmark'
Before I start on this project I want make sure what I am proposing is feasible. There is an unusual requirements I have to satisfy.
The model and formModel fields have to support a comment field on every field. I would like to be able to access them by object.field and object.field.comment. At first glance, this looks like I should have a separate type of comment and then somehow link it to correct field but is there a way to create a custom modelField that stores data in more then one database field from one or more form inputs? I would think there would have to be a custom widget to support this too?
If anyone has any ideas or examples of anything like this please respond.
I think this is the answer to my question. I have not tried it yet, but from the description it looks like what I need. https://docs.djangoproject.com/en/dev/ref/forms/widgets/#multiwidget
I'm developing web page with many type of users, each with different profiles properties. I would like to use built in auth system but:
a) I want to use django-registration.
b) I can point User.get_profile to only one profile model.
How to accomplish that in nice fashion?
I haven't used django-registration so I don't know what it entails. For the second part of your question one way would be to
Associate an UserProfile with every User
Add different kinds of ProfileProperty classes and link to them from UseProfile using a generic relationship.
I know, it is a bit of a stretch.
I'm not an expert nor in python, django or database but I encountered a somewhat similar issue few weeks ago and on #django someone advised me to use Generic relation to achieve that.
I created a UserProfile model that is liked (through a OneToOnefield) to the "true" profile, and using contrib.content-type and generic relation I'm able to use several distinct porfile types.
Note that should work for you if you don't fear to hit you database one more time on each get_profile().
An alternative would be to create a big table that contain all the field for all the profile type and using some kind of hook (or reimplementing a custom save()) to check the retired fields according the profile type. But it look complicated to me, especially if you want to have a lot of different profile type.
Another alternative could be to create a TextField derivated custom field and use it as a storage for a dictionary that you pickle to it on save and unpickle from it on load. With some hacking you could certainly map some of the model attribute to the dictionary key. That would allow a lot of flexibility.
Free hint for ya : I also use fixtures to test my application and forgot to check if the raw parameter of the post_save signal was True to prevent executing the UserProfile creation when using manage.py loaddata. As I had coded the creation of the "true" profile in my post_save callback the exception what kind of weird until I find out what was happening.
Usefull ressource :
defining a profile
generic relation