Skip to content

Latest commit

 

History

History
249 lines (182 loc) · 6.98 KB

README.md

File metadata and controls

249 lines (182 loc) · 6.98 KB
_|_|_|_|          _|
_|        _|_|_|  _|  _|      _|_|    _|  _|_|
_|_|_|  _|    _|  _|_|      _|_|_|_|  _|_|
_|      _|    _|  _|  _|    _|        _|
_|        _|_|_|  _|    _|    _|_|_|  _|

Faker is a Python package that generates fake data for you.

Whether you need to bootstrap your database, create good-looking XML documents, fill-in your persistence to stress test it, or anonymize data taken from a production service, Faker is for you.

See full documentation

Summary

Prerequisites

Starting from version 4.0.0, Faker dropped support for Python 2 and only supports Python 3.5 and above. If you still need Python 2 compatibility, please install version 3.0.1 in the meantime, and please consider updating your codebase to support Python 3 so you can enjoy the latest features Faker has to offer.

To install this tool, you will need:

  • Python library >=3.5
    • local
    • from a Docker container
  • pip (already installed if you are using Python 2 >=2.7.9 or Python 3 >=3.4))

Windows

Microsoft Visual C++ 14.0 (2015) with C++ Build Tools is required before installing pip. Note that while the error is calling for vc++ 14.0 - everything will work with newer versions of visual C++.

Install

pip install Faker

pip will install Faker in C:\Users\<username>\AppData\Local\Programs\Python\Python39\Scripts.

Usage

Use faker.Faker() to create and initialize a faker generator, which can generate data by accessing properties named after the type of data you want.

from faker import Faker

fake = Faker()

fake.name()
# 'Lucy Cechtelar'

fake.address()
# '426 Jordy Lodge
#  Cartwrightshire, SC 88120-6700'

fake.text()
# 'Sint velit eveniet. Rerum atque repellat voluptatem quia rerum. Numquam excepturi
#  beatae sint laudantium consequatur. Magni occaecati itaque sint et sit tempore. Nesciunt
#  amet quidem. Iusto deleniti cum autem ad quia aperiam.
#  A consectetur quos aliquam. In iste aliquid et aut similique suscipit. Consequatur qui
#  quaerat iste minus hic expedita. Consequuntur error magni et laboriosam. Aut aspernatur
#  voluptatem sit aliquam. Dolores voluptatum est.
#  Aut molestias et maxime. Fugit autem facilis quos vero. Eius quibusdam possimus est.
#  Ea quaerat et quisquam. Deleniti sunt quam. Adipisci consequatur id in occaecati.
#  Et sint et. Ut ducimus quod nemo ab voluptatum.'

Each call to method fake.name() yields a different (random) result. This is because faker forwards faker.Generator.method_name() calls to faker.Generator.format(method_name).

from faker import Faker

fake = Faker()

for _ in range(10):
  print(fake.name())

# 'Adaline Reichel'
# 'Dr. Santa Prosacco DVM'
# 'Noemy Vandervort V'
# 'Lexi O'Conner'
# 'Gracie Weber'
# 'Roscoe Johns'
# 'Emmett Lebsack'
# 'Keegan Thiel'
# 'Wellington Koelpin II'
# 'Ms. Karley Kiehn V'

Command line

When installed, you can invoke faker from the command-line:

faker [-h] [--version] [-o output]
      [-l {bg_BG,cs_CZ,...,zh_CN,zh_TW}]
      [-r REPEAT] [-s SEP]
      [-i {package.containing.custom_provider otherpkg.containing.custom_provider}]
      [fake] [fake argument [fake argument ...]]
faker address
# 968 Bahringer Garden Apt. 722
# Kristinaland, NJ 09890

faker -l de_DE address
# Samira-Niemeier-Allee 56
# 94812 Biedenkopf

faker profile ssn,birthdate
# {'ssn': u'628-10-1085', 'birthdate': '2008-03-29'}

faker -r=3 -s=";" name
# Willam Kertzmann;
# Josiah Maggio;
# Gayla Schmitt;

Localization

faker.Faker can take a locale as an argument, to return localized data. If no localized provider is found, the factory falls back to the default en_US locale. You can check available Faker locales in the source code, under the providers package.

from faker import Faker

fake = Faker('it_IT')

for _ in range(10):
    print(fake.name())

# 'Elda Palumbo'
# 'Pacifico Giordano'
# 'Sig. Avide Guerra'
# 'Yago Amato'
# 'Eustachio Messina'
# 'Dott. Violante Lombardo'
# 'Sig. Alighieri Monti'
# 'Costanzo Costa'
# 'Nazzareno Barbieri'
# 'Max Coppola'

faker.Faker also supports multiple locales. New in v3.0.0.

from faker import Faker

fake = Faker(['it_IT', 'en_US', 'ja_JP'])

for _ in range(10):
    print(fake.name())

# 鈴木 陽一
# Leslie Moreno
# Emma Williams
# 渡辺 裕美子
# Marcantonio Galuppi
# Martha Davis
# Kristen Turner
# 中津川 春香
# Ashley Castillo
# 山田 桃子

Unique values

Through use of the .unique property on the generator, you can guarantee that any generated values are unique for this specific instance.

from faker import Faker

fake = Faker()
names = [fake.unique.first_name() for i in range(500)]
assert len(set(names)) == len(names)

Seeding the Generator

When using Faker for unit testing, you will often want to generate the same data set. For convenience, the generator also provide a seed() method, which seeds the shared random number generator. Calling the same methods with the same version of faker and seed produces the same results.

from faker import Faker

fake = Faker()
Faker.seed(4321)

print(fake.name())
# 'Margaret Boehm'

Each generator can also be switched to its own instance of random.Random, separate to the shared one, by using the seed_instance() method, which acts the same way.

For example:

from faker import Faker

fake = Faker()
fake.seed_instance(4321)

print(fake.name())
# 'Margaret Boehm'

If you are using pytest, you can seed the faker fixture by defining a faker_seed fixture. See the Pytest Fixtures section below.

Pytest Fixtures

To run tests of an app, you might need reliable and clean data in your database. It is called fixtures. Faker also has its own pytest plugin which provides a faker fixture you can use in your tests. Please check out the pytest fixture docs to learn more.

To do this, use the plugin for Pytest faker.

pip install pytest-faker

Example tests/test_faker.py:

from faker.generator import Generator

def test_faker(faker):
    """Faker factory is a fixture."""
    assert isinstance(faker, Generator)
    assert isinstance(faker.name(), str)