计算数组中连续相等的值

Question

假设我有以下numpy数组：a = np.array([1,5,5,2,3,6,5,2,5,5,5])我试图想出一个numpy解决方案来计算给定值连续出现的次数。因此，例如对于5我想得到的数字：array([2,1,3])因为它在数组中连续出现 3 次，每次都有指定的重复次数。

Answer 1

这是改编自此答案的一个选项：

def count_consecutive(arr, n):

    # pad a with False at both sides for edge cases when array starts or ends with n

    d = np.diff(np.concatenate(([False], arr == n, [False])).astype(int))

    # subtract indices when value changes from False to True from indices where value changes from True to False

    return np.flatnonzero(d == -1) - np.flatnonzero(d == 1)

count_consecutive(a, 5)

# array([2, 1, 3])

Answer 2

如果你没问题，list那么可以使用 groupby

from itertools import groupby

a=[1,5,5,2,3,6,5,2,5,5,5]

[len(list(v)) for k,v in groupby(a) if k==5]

输出

[2, 1, 3]