Factory_boy 不创建不同的用户对象 Django

Question

I am new to Factory_boy with Django. After spending some time I understood how to create a factory for User model.

I am using the default user model and following is my factory. I am using Faker for randomness

import factory
from . import models
from django.contrib.auth.models import User
from faker import Faker
from django.contrib.auth.hashers import make_password

fake = Faker()

class UserFactory(factory.DjangoModelFactory):
    class Meta:
        model = User
        django_get_or_create = ('email',)

    first_name = fake.first_name()
    last_name = fake.last_name()
    email = first_name+"."+last_name+"@gmail.com"
    password = make_password("ojasojas")
    username = first_name+"_"+last_name

Now in the django shell

I use UserFactory.create() to crate an user. this works fine. Is it possible to loop through create statement and crate 5 different users? Now when I am doing that I am getting only one user (crated once and 'get' 4 times) as follows. What am I missing?

Answer 1

You are defining class attributes for your factory, which get evaluated only when the class is defined. email = first_name+"."+last_name+"@gmail.com" will be evaluated once, not each time you call UserFactory.create() , hence the unique constraint errors. The usual solution to this is to instead define instance attributes via __init__() , but FactoryBoy has their own solution to this: lazy attributes .

Answer 2

This may not be the best solution, but its a work around I've been using lately. I set the following Global:

NAMES = [factory.Faker('name')._get_faker().name() for i in range(5)]

In this case, the above will generate a list of 5 fake names.

NOTE: this does not guarantee a unique name (as FuzzyChoice will just select one from the list).

and within your factory:

name = factory.LazyAttribute(lambda obj: factory.fuzzy.FuzzyChoice(NAMES).fuzz()) 

Answer 3

FactoryBoy offers LazyFunction and LazyAttribute classes to achieve this. Difference between them is that you can access other model-factory fields in LazyAttribute .

Here is an example:

class UserFactory(factory.django.DjangoModelFactory):
    class Meta:
        model = models.User
        django_get_or_create = ('email',)
    
    @staticmethod
    def gen_email(x):
        return x.first_name + "." + x.last_name + "@gmail.com"
    
    first_name = factory.LazyFunction(fake.first_name)
    last_name = factory.LazyFunction(fake.last_name)
    email = factory.LazyAttribute(gen_email)
    password = make_password("ojasojas")
    username = factory.LazyAttribute(lambda x: x.first_name + "_" + x.last_name)

You can use lambda expressions as I've used here for demonstration in making the username field 'lazy-evaluated', or create functions (static method) and pass them to LazyFunction / LazyAttribute .

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You can read more about these classes in official documentation of Factory Boy:

• LazyFunction
• LazyAttribute