file.py

for cpt, elt_id in enumerate(input_ids):

    # Copy the background to the new image, then draw it
    new_bg = copy(bg_image)
    draw = ImageDraw.Draw(new_bg)

    # Generate a QR code as image
    qr_image = data_to_qrcode(elt_id)
    qr_x, qr_y = qr_image.size # Get width/height of QR code image

    # Paste the QR code image to the background
    # DELTA are used to change image placement (default is centered)
    DELTA_X = 0 # Keep the QR code horizontally centered
    DELTA_Y = 107 # Place the QR code according to the background
    new_bg.paste(qr_image,
                 (bg_x//2 - qr_x//2 + DELTA_X, bg_y//2 - qr_y//2 + DELTA_Y))

    # (Optinnal) Draw the ID on the card, just above the QR code
    draw.text((bg_x/2 - 240, 810), # No rule here, just try and adapt
              text=elt_id,
              font=fnt,
              fill=0)

    # Save the picture
    full_path = os.path.join(output_path, elt_id + '.' + OUTPUT_FORMAT)
    new_bg.save(full_path, OUTPUT_FORMAT)

    # Delete in-memory objects (they're not necessary anymore)
    del new_bg
    del qr_image