以一定的概率将 2 个值随机放入数组中

Question

我想通过分配列表 seq=[30,170] 的值在 python 中创建一个长度为 24 的随机数组。所以我想要一个看起来像 a=[30,30,30,170,30,170,...] 的数组。问题是，这些值不应该完全随机分配，而是以一定的概率分配。在这种情况下，如果第一个值为 30（或 170），则下一个值为 30（或 170）的概率也应为 90%，下一个值为 170（或 30）的概率应为10%。

有人知道怎么做吗？目前我只找到了如何随机排列它们。谢谢！！

import random
seq=[30,170] 
a = random.choices(seq,k=24)

Answer 1

您可以为random.choices(population, weights=None, *, cum_weights=None, k=1)提供权重。

您需要反复执行此操作才能在查找需要使用的权重时引用最后一个值：

import random

seq = [30, 170] 

# weight lookup
wgt = {30: (90, 10), 170:(10, 90)}

r = []

for _ in range(24):
    if not r:
        # need some initial value: 50/50
        r.append(random.choice(seq))
    else:          
        # k == 1, using correct weights from lookup, use only single value and add it
        r.append(random.choices(seq, weights=wgt[r[-1]], k=1)[0])

print(r)

8 次运行的输出：

[170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170]

[30, 30, 30, 30, 30, 30, 170, 170, 170, 170, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30]

[30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30]

[30, 30, 30, 30, 30, 170, 170, 170, 170, 170, 170, 170, 170, 30, 30, 170, 170, 170, 170, 170, 170, 170, 170, 170]

[170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 30, 30, 30, 170, 170, 170, 170]

[170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 170, 30, 30, 30, 30, 30, 30, 30, 30, 30]

[30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30]

[30, 30, 170, 170, 30, 170, 170, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30]

您也可以自己提供权重：

seq = [30,170]
w = {30: (30,30,30,30,30,30,30,30,30,170),           # if  30: use 9 * 30 + 1 * 170
     170:(30,170,170,170,170,170,170,170,170,170)}   # if 170: use 9 * 170 + 1 * 30

r = []
for _ in range(24):
    if not r:
        r.append(random.choice(seq))
    else:          
        r.append(random.choice(w[r[-1]]))

以一定的概率将 2 个值随机放入数组中

Place 2 values randomly in array with certain probability

python

random

probability