Django: Get list of all models and associated fields in a django project

Get the list of all the models and associated fields/attributes in a django project or an application

#django #python

Meet Gor

Context

Let's say we want the list of all the models and associated attributes in all the applications of a django project, we can do that using the django.apps with apps method.

Get all the models in a project

To fetch all the models, we can use the get_models methods, it will return a list of model classes in all the entire project(all applications). We can import all the models in the django project with the command: 

from django.apps import apps
models = apps.get_models()

[<class 'django.contrib.admin.models.LogEntry'>, <class 'django.contrib.auth.models.Permission'>, 
<class 'django.contrib.auth.models.Group'>, <class 'django.contrib.contenttypes.models.ContentType'>,
 <class 'django.contrib.sessions.models.Session'>, <class 'allauth.account.models.EmailAddress'>, 
<class 'allauth.account.models.EmailConfirmation'>, <class 'allauth.socialaccount.models.SocialApp'>, 
<class 'allauth.socialaccount.models.SocialAccount'>, <class 'allauth.socialaccount.models.SocialToken'>, 
<class 'user.models.TimeStampedModel'>, <class 'user.models.User'>, <class 'articles.models.Tags'>,
 <class 'articles.models.Series'>, <class 'articles.models.Article'>, <class 'blog.models.Blog'>]

We are importing the apps and creating a list of the models in our django project. The Django app command will load all the applications in the project, and the get_models method will fetch the associated models. This has resulted in a list of model class objects, we can iterate over them and fetch the required details, we want.

For instance, If I am interested in the name of these models, I can use the __name__ property to fetch the model's name. 

from django.apps import apps
model_list = apps.get_models()

for model in model_list:
    print(model.__name__)

LogEntry
Permission
Group
ContentType
Session
EmailAddress
EmailConfirmation
SocialApp
SocialAccount
SocialToken
TimeStampedModel
User
Tags
Series
Article
Blog

So, from the above example, we can see we have accessed all the model names in our entire django project.

Access Application name associated with a model

For accessing the name of the application from the model class, we can use the _meta attribute followed by the app_label property to get the app_name associated with the model. 

from django.apps import apps
model_list = apps.get_models()

for model in model_list:
    print(f"{model._meta.app_label}  -> {model.__name__}")

admin  -> LogEntry
auth  -> Permission
auth  -> Group
contenttypes  -> ContentType
sessions  -> Session
account  -> EmailAddress
account  -> EmailConfirmation
socialaccount  -> SocialApp
socialaccount  -> SocialAccount
socialaccount  -> SocialToken
user  -> TimeStampedModel
user  -> User
articles  -> Tags
articles  -> Series
articles  -> Article
blog  -> Blog

In the above example, we can see we have printed all the models with their associated application names.

Accessing all the attributes associated with a model

To access all the fields/property/attributes associated with a model, we can again use the _meta attribute followed by the get_fields method. This method will return a list of field objects. For accessing the name of those attributes/fields, we have to iterate over the list and then further use name property. 

from django.apps import apps
model_list = apps.get_models()
for model in model_list:
    print(model.__name__)
    field_list = model._meta.get_fields()
    for field in field_list:
        print(field.name)


LogEntry
id
action_time
user
content_type
object_id
object_repr
action_flag
change_message
Permission
group
user
id
...
...
Blog
article
id
name
description
authors
So, that is how we get all the associated field names in the associated models in our django projects. Also, there are a lot of attributes, we can access with the apps property. The __dict__.keys() can be used to get the list of all associated properties or other methods in a class instance. 

>>> m[14]._meta.get_fields()[4].__dict__.keys()

dict_keys(['name', 'verbose_name', '_verbose_name', 'primary_key', 'max_length', '_unique', 'blank', 'null', 'remote_field',
 'is_relation', 'default', 'editable', 'serialize', 'unique_for_date', 'unique_for_month', 'unique_for_year', 'choices', 
'help_text', 'db_index', 'db_column', '_db_tablespace', 'auto_created', 'creation_counter', '_validators', '_error_messages', 
'error_messages', 'db_collation', 'validators', 'attname', 'column', 'concrete', 'model'])
In the above example, I am using a list of models and getting the list of all the attributes associated with a field of a model. This can be applied and other properties can be accessed.

Get Models with a specific app

Let's say we want all the models associated with a particular application in the project, we can do that by specifying the name of the application. 

from django.apps import apps

app_info = apps.get_app_config('articles')

print(app_info.__dict__.keys()

print(app_info.verbose_name)

print(app_info.models)

print(app_info.models['article'].__dict__.keys())

dict_keys(['name', 'module', 'apps', 'label', 'verbose_name', 'path', 'models_module', 'models'])

'Article'

{'tags': <class 'articles.models.Tags'>, 'series': <class 'articles.models.Series'>, 'article': <class 'articles.models.Article'>}

dict_keys(['__module__', 'Article_Status', '__str__', 'get_absolute_url', '__doc__', '_meta', 'DoesNotExist', 'MultipleObjectsReturned', 'title', 'description', 'content', 'status', 'get_status_display', 'blog_id', 'blog', 'author_id', 'author', 'timestampedmodel_ptr_id', 'timestampedmodel_ptr'])

So, we can see that we have got the information about the app articles in the proejct where we can get the verbose_name property to fetch the human-readable format of the article model. Further, we can get all the models associated with the articles application. We get back a dict with the model name as the key and the class reference as the value.

We have accessed the article model in the articles application and fetched all the associated properties or methods in the model.

For further references, you can visit the django apps documentation to get more relevant methods and properties.