from PIL import Image
import os

def getFolders(dir):
    return [name for name in os.listdir(dir)
            if os.path.isdir(os.path.join(dir, name))]

def getFiles(dir):
    files = []
    for c in os.listdir(dir):
        _, ext = os.path.splitext(c)

        if ext == '.png':
            files.append(c)

    return files

def merge_images(dir, file):
    image = Image.open(os.path.join(dir, file))
    base = Image.open(out_file)

    (width1, height1) = image.size
    (width2, height2) = base.size

    result_width = max(width1, width2)
    result_height = height1 + height2

    out = Image.new('RGB', (result_width, result_height))
    out.paste(im=base, box=(0, 0))
    out.paste(im=image, box=(0, height2))

    out.save(out_file,"PNG")
    return out

def createTarget():
    result = Image.new('RGB', (1, 1))
    result.save(out_file,"PNG")
    
dir = '/Users/user/Documents/C5'
dir1 = dir
folder = getFolders(dir)

for i in range(len(folder)):
    dir = dir1 + folder[i]
    ff = getFiles(dir)
    out_file = folder[i] + '.png'
    createTarget()
    for f in ff:
        merge_images(dir, f)
    print(folder[i] + ': Done.')
print('All done!')