How can i properly use random.sample in my code?

Question

My directory has hundreds of images and text files(.png and .txt). what's special about them is that each image has its own matching txt file, for example im1.png has img1.txt, news_im2.png has news_im2.png etc.. What i want is some way to give it a parameter or percentage, let's say 40 where it randomly copy 40% of the images along with their correspondent texts to a new file, and the most important word here is randomely as if i do the test again i shouldn't get the same results. Ideally i should be able to take 2 kind of parameters(reminder that the first would be the % of each sample) the second being number of samples for example maybe i want my data in 3 different samples randomly not only 2, in this case it should be able to take destination directories path equal to the number of samples i want and spread them accordingly, for example i shouldn't find img_1 in 2 different samples.

What i have done so far is simply set up my method to copy them :

import glob, os, shutil


source_dir ='all_the_content/'
dest_dir = 'percentage_only/'
files = glob.iglob(os.path.join(source_dir, "*.png"))
for file in files:
     if os.path.isfile(file):
         shutil.copy2(file, dest_dir)

and the start of my code to set the random switching:

import os, shutil,random

my_pic_dict = {}
source_dir ='/home/michel/ubuntu/EAST/data_0.8/'

for element in os.listdir(source_dir):
    if element.endswith('.png'):
        my_pic_dict[element] = element.replace('.png', '.txt')
print(my_pic_dict)
print (len(my_pic_dict))
imgs_list = my_pic_dict.keys()
print(imgs_list)

hwo can i finalize it as i couldn't make random.sample work.

Answer 1

try this:

import random
import numpy as np

n_elem = 1000
n_samples = 4
percentages = [50,10,10,30]
indices = list(range(n_elem))
random.shuffle(indices)
elem_per_samples = [int(p*n_elem/100) for p in percentages]
limits = np.cumsum([0]+elem_per_samples)
samples = [indices[limits[i]:limits[i+1]] for i in range(n_samples)]