simple_labeler.py

import os
from PIL import Image

base_dir = 'image manually'
with open('label_file.txt', 'w') as of:
    for filename in os.listdir(base_dir):
        print('Labeling filename', filename)
        img = Image.open(os.path.join(base_dir, filename))
        img.show()
        label = input('Flood = 0, Non-flood=1: ')
        of.write('{}\t{}\n'.format(filename, label))
        img.close()
        of.flush()