Django: Get list of model fields?

DjangoDjango Models

Django Problem Overview


I've defined a User class which (ultimately) inherits from models.Model. I want to get a list of all the fields defined for this model. For example, phone_number = CharField(max_length=20). Basically, I want to retrieve anything that inherits from the Field class.

I thought I'd be able to retrieve these by taking advantage of inspect.getmembers(model), but the list it returns doesn't contain any of these fields. It looks like Django has already gotten a hold of the class and added all its magic attributes and stripped out what's actually been defined. So... how can I get these fields? They probably have a function for retrieving them for their own internal purposes?

Django Solutions


Solution 1 - Django

Django versions 1.8 and later:

You should use get_fields():

[f.name for f in MyModel._meta.get_fields()]

The get_all_field_names() method is deprecated starting from Django 1.8 and will be removed in 1.10.

The documentation page linked above provides a fully backwards-compatible implementation of get_all_field_names(), but for most purposes the previous example should work just fine.


Django versions before 1.8:

model._meta.get_all_field_names()

That should do the trick.

That requires an actual model instance. If all you have is a subclass of django.db.models.Model, then you should call myproject.myapp.models.MyModel._meta.get_all_field_names()

Solution 2 - Django

As most of answers are outdated I'll try to update you on Django 2.2 Here posts- your app (posts, blog, shop, etc.)

1) From model link: https://docs.djangoproject.com/en/stable/ref/models/meta/

from posts.model import BlogPost

all_fields = BlogPost._meta.fields
#or
all_fields = BlogPost._meta.get_fields()

Note that:

all_fields=BlogPost._meta.get_fields()

Will also get some relationships, which, for ex: you can not display in a view.
As in my case:

Organisation._meta.fields
(<django.db.models.fields.AutoField: id>, <django.db.models.fields.DateField: created>...

and

Organisation._meta.get_fields()
(<ManyToOneRel: crm.activity>, <django.db.models.fields.AutoField: id>, <django.db.models.fields.DateField: created>...

2) From instance

from posts.model import BlogPost

bp = BlogPost()
all_fields = bp._meta.fields

3) From parent model

Let's suppose that we have Post as the parent model and you want to see all the fields in a list, and have the parent fields to be read-only in Edit mode.

from django.contrib import admin
from posts.model import BlogPost 

@admin.register(BlogPost)
class BlogPost(admin.ModelAdmin):
    all_fields = [f.name for f in Organisation._meta.fields]
    parent_fields = BlogPost.get_deferred_fields(BlogPost)

    list_display = all_fields
    read_only = parent_fields

Solution 3 - Django

The get_all_related_fields() method mentioned herein has been deprecated in 1.8. From now on it's get_fields().

>> from django.contrib.auth.models import User
>> User._meta.get_fields()

Solution 4 - Django

I find adding this to django models quite helpful:

def __iter__(self):
    for field_name in self._meta.get_all_field_names():
        value = getattr(self, field_name, None)
        yield (field_name, value)

This lets you do:

for field, val in object:
    print field, val

Solution 5 - Django

This does the trick. I only test it in Django 1.7.

your_fields = YourModel._meta.local_fields
your_field_names = [f.name for f in your_fields]

Model._meta.local_fields does not contain many-to-many fields. You should get them using Model._meta.local_many_to_many.

Solution 6 - Django

It is not clear whether you have an instance of the class or the class itself and trying to retrieve the fields, but either way, consider the following code

Using an instance

instance = User.objects.get(username="foo")
instance.__dict__ # returns a dictionary with all fields and their values
instance.__dict__.keys() # returns a dictionary with all fields
list(instance.__dict__.keys()) # returns list with all fields

Using a class

User._meta.__dict__.get("fields") # returns the fields

# to get the field names consider looping over the fields and calling __str__()
for field in User._meta.__dict__.get("fields"):
    field.__str__() # e.g. 'auth.User.id'

Solution 7 - Django

def __iter__(self):
    field_names = [f.name for f in self._meta.fields]
    for field_name in field_names:
        value = getattr(self, field_name, None)
        yield (field_name, value)

This worked for me in django==1.11.8

Solution 8 - Django

MyModel._meta.get_all_field_names() was deprecated several versions back and removed in Django 1.10.

Here's the backwards-compatible suggestion from the docs:

from itertools import chain

list(set(chain.from_iterable(
    (field.name, field.attname) if hasattr(field, 'attname') else (field.name,)
    for field in MyModel._meta.get_fields()
    # For complete backwards compatibility, you may want to exclude
    # GenericForeignKey from the results.
    if not (field.many_to_one and field.related_model is None)
)))

Solution 9 - Django

Just to add, I am using self object, this worked for me:

[f.name for f in self.model._meta.get_fields()]

Solution 10 - Django

At least with Django 1.9.9 -- the version I'm currently using --, note that .get_fields() actually also "considers" any foreign model as a field, which may be problematic. Say you have:

class Parent(models.Model):
    id = UUIDField(primary_key=True)

class Child(models.Model):
    parent = models.ForeignKey(Parent)

It follows that

>>> map(lambda field:field.name, Parent._model._meta.get_fields())
['id', 'child']

while, as shown by @Rockallite

>>> map(lambda field:field.name, Parent._model._meta.local_fields)
['id']

Solution 11 - Django

So before I found this post, I successfully found this to work.

Model._meta.fields

It works equally as

Model._meta.get_fields()

I'm not sure what the difference is in the results, if there is one. I ran this loop and got the same output.

for field in Model._meta.fields:
    print(field.name)

Solution 12 - Django

A detail not mentioned by others:

[f.name for f in MyModel._meta.get_fields()]

get, for example

['id', 'name', 'occupation']

and

[f.get_attname() for f in MyModel._meta.get_fields()]

get

['id', 'name', 'occupation_id']

If

reg = MyModel.objects.first()

then

reg.occupation

get, for example

<Occupation: Dev>

and

reg.occupation_id

get

1

Solution 13 - Django

> In sometimes we need the db columns as well:

def get_db_field_names(instance):
   your_fields = instance._meta.local_fields
   db_field_names=[f.name+'_id' if f.related_model is not None else f.name  for f in your_fields]
   model_field_names = [f.name for f in your_fields]
   return db_field_names,model_field_names

Call the method to get the fields:

db_field_names,model_field_names=get_db_field_names(Mymodel)

Solution 14 - Django

Combined multiple answers of the given thread (thanks!) and came up with the following generic solution:

class ReadOnlyBaseModelAdmin(ModelAdmin):
    def has_add_permission(self, request):
        return request.user.is_superuser

    def has_delete_permission(self, request, obj=None):
        return request.user.is_superuser

    def get_readonly_fields(self, request, obj=None):
        return [f.name for f in self.model._meta.get_fields()]

Solution 15 - Django

Why not just use that:

manage.py inspectdb

Example output:

class GuardianUserobjectpermission(models.Model):
    id = models.IntegerField(primary_key=True)  # AutoField?
    object_pk = models.CharField(max_length=255)
    content_type = models.ForeignKey(DjangoContentType, models.DO_NOTHING)
    permission = models.ForeignKey(AuthPermission, models.DO_NOTHING)
    user = models.ForeignKey(CustomUsers, models.DO_NOTHING)

    class Meta:
        managed = False
        db_table = 'guardian_userobjectpermission'
        unique_together = (('user', 'permission', 'object_pk'),)

Attributions

All content for this solution is sourced from the original question on Stackoverflow.

The content on this page is licensed under the Attribution-ShareAlike 4.0 International (CC BY-SA 4.0) license.

Content TypeOriginal AuthorOriginal Content on Stackoverflow
QuestionmpenView Question on Stackoverflow
Solution 1 - DjangorossipediaView Answer on Stackoverflow
Solution 2 - DjangoMaks View Answer on Stackoverflow
Solution 3 - DjangoWilView Answer on Stackoverflow
Solution 4 - DjangobjwView Answer on Stackoverflow
Solution 5 - DjangoRockalliteView Answer on Stackoverflow
Solution 6 - DjangoNader AlexanView Answer on Stackoverflow
Solution 7 - DjangoVivek AnandView Answer on Stackoverflow
Solution 8 - DjangoaboutaaronView Answer on Stackoverflow
Solution 9 - Djangoarrt_View Answer on Stackoverflow
Solution 10 - DjangokeepAliveView Answer on Stackoverflow
Solution 11 - DjangoCarl BrubakerView Answer on Stackoverflow
Solution 12 - DjangoAnselmo Blanco DominguezView Answer on Stackoverflow
Solution 13 - DjangoRamesh PonnusamyView Answer on Stackoverflow
Solution 14 - DjangoTobias ErnstView Answer on Stackoverflow
Solution 15 - DjangoAdam PawluczukView Answer on Stackoverflow