Split a dataset into many subsets of same size

Hello everyone,

To the end of conducting different experiments with different subsets of the same dataset, I would like to divide my dataset into many subsets. Let us assume that I have 100 images in a folder, I would like to divide the 100 images into five susets of 20 images without repetition. Subsequently, four of the subsets will be combined and saved as training set and the other set as test set. I aim to perform this same experiment five times given that the the dataset will be divided into five distinct subsets. Please, how can this be implemented? Any suggestions and comments would be highly appreciated.