参考API:https://docs.scipy.org/doc/numpy/reference/routines.random.html 1. numpy.random.shuffle() API中关于该函数是这样描述的: Modify a sequence in-place by shuffling its contents. This function only shuffles the array along the first axis of a multi-dimensional…
numpy.random.shuffle(x) Modify a sequence in-place by shuffling its contents. Parameters: x : array_like The array or list to be shuffled. Returns: None Examples >>> >>> arr = np.arange(10) >>> np.random.shuffle(arr) >>>…
randomly choose a sample of k items from a list S containing n elements, the algorithm may be online (i.e. the input list is unknown beforehand) https://en.wikipedia.org/wiki/Reservoir_sampling ReserviorSampling(Source[..n], Result[..k]) { ; i <= k;…
random.shuffle()是一个非常实用但是又非常容易被忽略的函数,shuffle在英语里是"洗牌"的意思,该函数非常形象地模拟了洗牌的过程,即: random.shuffle(x)表示对列表x中的所有元素随机打乱顺序(若x不是列表,则报错).此函数会直接对x本身进行操作,函数的返回值为None,即如果想对列表x进行洗牌,须使用random.shuffle(x)的形式,而不能使用y=random.shuffle(x)的形式. 示例代码: import random x = [1,…
If given a function that generates a random number from 1 to 5, how do you use this function to generate a random number from 1 to 7 with the same probability? (ie. function a has probability 1/5 per number, function b would have probability 1/7). in…