python数组符号简写:"k%parents.shape[0]"是什么意思？

Question

我今天遇到这个符号本教程在这里:https://towardsdatascience.com/genetic-algorithm-implementation-in-python-5ab67bb124a6

parent1_idx = k%parents.shape[0]

右边会返回什么？这种表达方式叫什么名字？预先感谢!

Answer 1

我在上述文章的代码片段中看到了这一行:

for k in range(offspring_size[0]):
     # Index of the first parent to mate.
     parent1_idx = k%parents.shape[0]
     # Index of the second parent to mate.
     parent2_idx = (k+1)%parents.shape[0]

其中parents定义如下:

parents = numpy.empty((num_parents, pop.shape[1]))
for parent_num in range(num_parents):
    max_fitness_idx = numpy.where(fitness == numpy.max(fitness))
    max_fitness_idx = max_fitness_idx[0][0]
    parents[parent_num, :] = pop[max_fitness_idx, :]
    fitness[max_fitness_idx] = -99999999999
return parents

从上面两行中，很明显 k 和 parents.shape[0] 都是整数，因此该行是一个简单的 modulo operator两个数值变量之间:a = b % c。