smicka.py

#! python3
import os, re
from datetime import datetime
from PIL import Image

SOURCE_DIR = 'C:/Users/David/Desktop/smicka/'
FINAL_PATH = 'C:/Users/David/Desktop/smicka.png'

pattern = re.compile('^[0-9]+\.(png|jpg|jpeg)$')
files = []
width = 0
height = 0
start = datetime.now()

for f in os.listdir(SOURCE_DIR):
    if pattern.match(f):
        img = Image.open(SOURCE_DIR+f)
        height += img.size[1]
        width = img.size[0] if width < img.size[0] else width
        files.append(f)
    
files.sort(key=lambda i: int(i.split('.')[0]), reverse=True)

print('Computed dimensions: ', width, 'x', height, '|', 'Images count:', len(files))

largeImg = Image.new('RGB', (width, height), (255, 255, 255))
y = 0

for fn in files:
    img = Image.open(SOURCE_DIR+fn)
    largeImg.paste(img, (0, y))
    y += img.size[1]

largeImg.save(FINAL_PATH)

print('Done in '+str(round((datetime.now() - start).total_seconds(), 2))+'s')
print('Saved as ', FINAL_PATH)
os.system('pause')