model_mommy is a tool for creating objects for testing in Django, inspired in ruby's ObjectDaddy and FactoryGirl. It generate the values according with the field type, but i will add support to custom values as well.

#Installing

pip install model_mommy

If you have a model like this in your app:

class Kid(models.Model):
    happy = models.BooleanField()
    name = models.CharField(max_length=30)
    age = models.IntegerField()
    bio = models.TextField()
    wanted_games_qtd = models.BigIntegerField()
    birthday = models.DateField()
    appointment = models.DateTimeField()

just call the mommy =):

from model_mommy import mommy
from model_mommy.models import Kid

kid = mommy.make_one(Kid)

and your object is created! No boring attributes passing like 'foobar' every damn time.

mommy also handles relationships. Suppose the kid has a dog:

class Dog(models.Model):
    owner = models.ForeignKey('Kid')

when you do:

rex = mommy.make_one(Dog)

it will also create the Kid, automatically.

You can also pass arguments to make one.

another_kid = mommy.make_one(Kid, {'age':3})
assert(another_kid.age == 3)

But, if don't need a persisted object, mommy can handle this for you as well:

from model_mommy import mommy
from model_mommy.models import Kid

kid = mommy.prepare_one(Kid)

It works like make_one, but like was said, it doesn't persist the instance.

Model instances can also be generated from Mommy factories. Make your mass producer mom like this:

from model_mommy.mommy import Mommy
from model_mommy.models import Kid

mom = Mommy(Kid)
first_kid = mom.make_one()
second_kid = mom.make_one()
third_kid = mom.make_one()

Note that this kind of construction is much more efficient than mommy.make_one(Model), so, if you need to create a lot of instances, this much be a nicier approach.

All attributes used to automatically populate mommy generated instances are created with generators from model_mommy/generators.py. If you want a specific field to be populated with a different generator from the default generator, you must extend the Mommy class to get this behavior. Let's see a example:

from model_mommy.generators import gen_from_list
from model_mommy.models import Kid
from model_mommy.mommy import Mommy

a_lot_of_games = range(30, 100)

class HardGamerMommy(Mommy):
    attr_mapping = {
        'wanted_games_qtd':gen_from_list(a_lot_of_games)
    }

mom = HardGamerMommy(Kid)
kid = mom.make_one()
assert(kid.wanted_games_qtd in a_lot_of_games)

You can also change the default generator for a field. Let's take a look:

from random import randint
from model_mommy.models import Kid
from model_mommy.mommy import Mommy

class KidMommy(Mommy):
    attr_mapping = {
        'wanted_games_qtd':gen_from_list(a_lot_of_games)
    }

mom = HardGamerMommy(Kid)
kid = mom.make_one()
assert(kid.wanted_games_qtd in a_lot_of_games)

Note that you can also create your own generator.

A generator is just a simple callable (like a function) that may require a few arguments. Let's see a dead simple example:

gen_newborn_age = lambda:0

class BabeMommy(Mommy):
    attr_mapping = {'age':gen_newborn_age}

mom = BabeMommy(Kid)
baby = mom.make_one()
assert(baby.age==0)

If the generator requires a attribute of field as argument, you could do something like this:

gen_name_from_default = lambda default_value:default_value
gen_name_from_default.required = ['default']

For more examples, see tests.

##Currently supports the fields: CharField, TextField, FloatField, ForeignKey, Date and DateTimeField, BooleanField, and all the integer-type Fields