fluffycow 0.0.5

A domain-specific language for generating random inputs

A simple and elegant library for generating complex random objects in Python.

(image credit: Matt Lautner.)

Installation

To install the latest release from PyPI:

$ pip install fluffycow

To install the latest development release:

$ git clone https://github.com/ChrisTimperley/fluffycow
$ cd fluffycow
$ python setup.py install

Examples

To generate 10 lists containing 5 random numbers:

import fluffycow as g

gen = g.list(g.random(), 5)
for i in range(10):
    l = next(gen)
    print(l)

"""
[0.8620918485892981, 0.4794836848262348, 0.262162063050416, 0.01909426938513137, 0.36506899628784006]
[0.9397902843125912, 0.9883123343094299, 0.5728170848781718, 0.2430986751635641, 0.6504376531611539]
[0.6530962809522628, 0.629805285301596, 0.7484217313556808, 0.4781887755635098, 0.7702516815623411]
[0.6049464336804768, 0.6857354552123759, 0.4401119070721792, 0.16269631684472152, 0.4501522526776762]
[0.6754685790929789, 0.14883325162091654, 0.7543575544723128, 0.7400186451945051, 0.7872586706933858]
[0.6093352430215464, 0.601878065077082, 0.9864251783225236, 0.5652106608585465, 0.2000072917817054]
[0.5288773016226057, 0.3473820645776373, 0.5181819860433858, 0.9795605815396756, 0.0941069188895195]
[0.577403816680611, 0.6006088487133505, 0.7401053882982396, 0.9243339819764703, 0.8737058738019327]
[0.15168246955860343, 0.9826794936881696, 0.8700116634339362, 0.23066589924280112, 0.6455718073363804]
[0.4953407037944514, 0.4235910957127196, 0.9817109582233142, 0.19140229868504488, 0.4238482591507997]
"""

To generate 5 random cows 🐄:

import fluffycow as g
import attr

@attr.s
class Cow:
   age = attr.ib(type=int)
   fluffiness = attr.ib(type=float)

# provide generators for each keyword argument,
gen = g.factory(Cow,
                age=g.randint(0, 50),
                fluffiness=g.gauss(5.0, 1.5))

# or for each positional argument,
gen = g.factory(Cow, g.randint(0, 50), g.gauss(5.0, 1.5))

# or mix positional and keyword arguments
gen = g.factory(Cow,
                g.randint(0, 50),
                fluffiness=g.gauss(5.0, 1.5))

# generate some fluffy cows
for i in range(5):
   cow = next(gen)
   print(cow)

"""
Cow(age=16, fluffiness=6.737730437364233)
Cow(age=30, fluffiness=3.6106200949734806)
Cow(age=4, fluffiness=5.856278892241928)
Cow(age=40, fluffiness=4.274460173984223)
Cow(age=8, fluffiness=4.26886806010291)
"""

To generate a farm containing a random mixture of 10 animals:

@attr.s
class Cow:
   age = attr.ib(type=int)
   fluffiness = attr.ib(type=float)

@attr.s
class Chicken:
    sass = attr.ib(type=int)

@attr.s
class Sheep:
   fluffiness = attr.ib(type=float)

def farm():
    cows = g.factory(Cow,
             age=g.randint(0, 30),
             fluffiness=g.gauss(5.0, 1.5))
    chickens = g.object(Chicken, g.randint(0, 10))
    sheep = g.object(Sheep, g.gauss(4.5, 1.0))

    animals = g.mux(cows, chickens, sheep)
    for i in range(10):
        animal = next(animals)
        print(animal)

"""
Cow(age=15, fluffiness=4.13522619329628)
Cow(age=6, fluffiness=6.132266751335851)
Sheep(fluffiness=4.996947740687185)
Cow(age=25, fluffiness=4.268442712380023)
Sheep(fluffiness=4.92952572321737)
Chicken(sass=5)
Cow(age=28, fluffiness=5.155204522890905)
Sheep(fluffiness=3.9241924681246094)
Sheep(fluffiness=3.676097181435127)
Sheep(fluffiness=2.713429568549102)
"""