Python Standard Library

The whrandom Module

The whrandom module, shown in Example 2-33, provides a pseudo-random number generator (based on an algorithm by Wichmann and Hill, 1982). Unless you need several generators that do not share internal state (for example, in a multithreaded application), it’s better to use the functions in the random module instead.

Example 2-33. Using the whrandom Module

File: whrandom-example-1.py

import whrandom

# same as random
print whrandom.random()
print whrandom.choice([1, 2, 3, 5, 9])
print whrandom.uniform(10, 20)
print whrandom.randint(100, 1000)

0.113412062346
1
16.8778954689
799

Example 2-34 shows how to create multiple generators by creating instances of the whrandom class.

Example 2-34. Using the whrandom Module to Create Multiple Random Generators

File: whrandom-example-2.py

import whrandom

# initialize all generators with the same seed
rand1 = whrandom.whrandom(4,7,11)
rand2 = whrandom.whrandom(4,7,11)
rand3 = whrandom.whrandom(4,7,11)

for i in range(5):
    print rand1.random(), rand2.random(), rand3.random()

0.123993532536 0.123993532536 0.123993532536
0.180951499518 0.180951499518 0.180951499518
0.291924111809 0.291924111809 0.291924111809
0.952048889363 0.952048889363 0.952048889363
0.969794283643 0.969794283643 0.969794283643