factory-boy
A versatile test fixtures replacement based on thoughtbot's factory_bot for Ruby.
Decision gist · record as of 2026-08-14
Yes. factory_boy is a mature, widely-used testing library (top 1000 PyPI, 22937878 monthly downloads) with no known vulnerabilities, permissive MIT license, and low install friction. Its aging maintenance status (557 days since release) is offset by a stable, well-documented codebase and active repository. Install it if you write tests for ORM-backed applications or complex object hierarchies.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- ORM integration (Django, SQLAlchemy, MongoEngine) required for .create() strategy; .build() and .stub() work without external ORMs.
- Low install friction with a single runtime dependency (Faker).
- Maintenance status is aging—557 days since last release—but the repository remains active with 3806 stars.
License · maintenance · safety
MIT (permissive) — MIT license (permissive) allows unrestricted use, modification, and distribution in commercial and private projects with minimal obligations.
last release 2025-02-03 (557 days) · last repo commit 2026-01-01 · 3,806 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 22,937,878 downloads/mo, #963 on PyPI
Alternatives
Verify before relying
pip install factory-boy
import factory
class UserFactory(factory.Factory):
class Meta:
model = User
first_name = 'John'
last_name = 'Doe'
user = UserFactory.build() # Unsaved instance
user = UserFactory.create() # Saved instance (requires ORM)- Whether Faker integration is automatic or requires explicit configuration for realistic value generation.
- Performance characteristics when generating large batches of objects in test suites.
- Compatibility details with specific ORM versions beyond Django 4.2, 5.0, 5.1.
What it is and what it does
factory_boy is a test fixture library that replaces hard-coded, static test data with declarative factory classes. Instead of manually constructing complex nested objects with all their dependencies for each test, you define a factory once and then instantiate customized instances by specifying only the fields relevant to the current test. It integrates with popular ORMs and supports multiple instantiation strategies: build (unsaved), create (saved), and stub (plain attributes).
The library reduces boilerplate in test setup by allowing you to chain factory calls, override attributes inline, generate batches of objects, and use lazy attributes or sequences for computed or unique values. It relies on Faker for generating realistic random data, and provides helpers for reproducible random seeding in tests. This makes test code more readable and maintainable, especially for complex domain models with many relationships.
Use it for
- Define reusable factories for models to avoid repeating address, user, and order setup across test files.
- Generate batches of test records with realistic names and emails using Faker integration for demos or load testing.
- Create nested object hierarchies using SubFactory without manually instantiating each level.
- Override specific fields per test while keeping defaults for unchanged attributes.
- Build unsaved instances for unit tests and saved instances for integration tests using the same factory.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes.
factory_boy is a mature, widely-used testing library (top 1000 PyPI, 22937878 monthly downloads) with no known vulnerabilities, permissive MIT license, and low install friction. Its aging maintenance status (557 days since release) is offset by a stable, well-documented codebase and active repository. Install it if you write tests for ORM-backed applications or complex object hierarchies.
Install
factory-boy on PyPI
Before you install
Low install friction with a single runtime dependency (Faker). Maintenance status is aging—557 days since last release—but the repository remains active with 3806 stars.
ORM integration (Django, SQLAlchemy, MongoEngine) required for .create() strategy; .build() and .stub() work without external ORMs.
License in practice
MIT license (permissive) allows unrestricted use, modification, and distribution in commercial and private projects with minimal obligations.
Quickstart
pip install factory-boy
import factory
class UserFactory(factory.Factory):
class Meta:
model = User
first_name = 'John'
last_name = 'Doe'
user = UserFactory.build() # Unsaved instance
user = UserFactory.create() # Saved instance (requires ORM)Verify before relying
- Whether Faker integration is automatic or requires explicit configuration for realistic value generation.
- Performance characteristics when generating large batches of objects in test suites.
- Compatibility details with specific ORM versions beyond Django 4.2, 5.0, 5.1.
Package facts
| License | MIT permissive |
| Python support | Supports the current Python release >=3.8 |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | 1 packageFaker |
| Maintenance | Aging 557 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 22,937,878 / month, #963 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 5 - Production/StableFramework :: DjangoFramework :: Django :: 4.2Framework :: Django :: 5.0Framework :: Django :: 5.1Intended Audience :: DevelopersLicense :: OSI Approved :: MIT LicenseOperating System :: OS IndependentProgramming Language :: PythonProgramming Language :: Python :: 3Programming Language :: Python :: 3 :: OnlyProgramming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Programming Language :: Python :: 3.9Programming Language :: Python :: Implementation :: CPythonProgramming Language :: Python :: Implementation :: PyPyTopic :: Software Development :: Libraries :: Python ModulesTopic :: Software Development :: Testing |
Evidence: factory_boy-3.3.3-py2.py3-none-any.whl
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See also async-factory-boy · pytest-factoryboy · wagtail-factories · model-mommy · types-factory-boy · objectory · mixer · pytest-docker-tools · fake-factory · pytest-rabbitmq