How to get a list of the fields in a Django model?

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?

Solution

As most of answers are outdated I'll try to update you on Django 2.2 Here posts- your app (posts, blog, shop, etc.)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