Using random module

korakot (Korakot Chaovavanich) — Mon, 06 Mar 2006 23:04:16 GMT



>>> import random



>>> # 0.0 <= float < 1.0

>>> random.random()

0.41360177662769904



>>> # 10.0 <= float < 20.0

>>> random.uniform(10,20)

15.743669918803288



>>> # 10 <= int <= 20  (can be 20)

>>> random.randint(10,20)

10



>>> # 10 <= int < 20  (even only, coz step=2)

>>> random.randrange(10,20,2)

16



>>> # choose from a list

>>> random.choice([1, 2, 3, 5, 9])

2



>>> # make a list into random order

>>> cards = range(52)

>>> random.shuffle(cards)  # order is random now

>>> cards[:5]   # get 5 cards

[37, 14, 42, 44, 6]

Weighted random choice

korakot (Korakot Chaovavanich) — Sat, 17 Sep 2005 05:41:27 GMT

From Kevin Parks's recipe



import random



def w_choice(lst):

	n = random.uniform(0, 1)

	for item, weight in lst:

		if n < weight:

			break

		n = n - weight

	return item

Usage, similar to random.choice but must specify probabilities.



>>> x = w_choice( [('one',0.25), ('two',0.25), ('three',0.5)] )

DZone Snippets: choice code

Using random module

Weighted random choice