python random 模块, numpy.random模块

Warning小心：这个模块不可用作安全方面的防护，安全方面需要看 secrets 模块

以下代码摘自官网。

1. 基础功能：产生随机数

以下的产生随机数均为产生一个随机数；choice（）也是选一个。choice（），sample（）限定k值可以取一段数据。

>>>from random import *
>>> random()                             # Random float:  0.0 <= x < 1.0
0.37444887175646646

>>> uniform(2.5, 10.0)                   # Random float:  2.5 <= x < 10.0
3.1800146073117523

>>> expovariate(1 / 5)                   # Interval between arrivals averaging 5 seconds
5.148957571865031

>>> randrange(10)                        # Integer from 0 to 9 inclusive
7

>>> randrange(0, 101, 2)                 # Even integer from 0 to 100 inclusive
26

>>> choice(['win', 'lose', 'draw'])      # Single random element from a sequence
'draw'

>>> deck = 'ace two three four'.split()
>>> shuffle(deck)                        # Shuffle a list
>>> deck
['four', 'two', 'ace', 'three']

>>> sample([10, 20, 30, 40, 50], k=4)    # Four samples without replacement
[40, 10, 50, 30]`

>>> # Six roulette wheel spins (weighted sampling with replacement)
>>> choices(['red', 'black', 'green'], [18, 18, 2], k=6)
['red', 'green', 'black', 'black', 'red', 'black']

2. 模拟产生次数，计算概率

注意算出来的概率每次都不一样。

>>> # Deal 20 cards without replacement from a deck of 52 playing cards
>>> # and determine the proportion of cards with a ten-value
>>> # (a ten, jack, queen, or king).
>>> deck = collections.Counter(tens=16, low_cards=36)
>>> seen = sample(list(deck.elements()), k=20)
>>> seen.count('tens') / 20
0.15  

3. 结合numpy模块使用

差不多，引入了数组功能。

参考资料：

1. 为什么你用不好Numpy的random函数？
2. 官网
   https://docs.scipy.org/doc/numpy/reference/routines.random.html

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参考资料：

1. 官网 https://docs.python.org/3/library/random.html
2. Capricorn的实验室 , Python中的random模块
3. Python random模块
4. 为什么你用不好Numpy的random函数？

2018.5.14