A program that memorizes your dock size

dock-memory.py

#!/usr/bin/env python3

import sys
import subprocess
import ctypes
import argparse

hi_dll = ctypes.CDLL('/System/Library/Frameworks/ApplicationServices.framework/ApplicationServices')

def save_dock_size():
    get_size_func = hi_dll.CoreDockGetTileSize
    get_size_func.restype = ctypes.c_float
    cur_size = get_size_func()
    subprocess.run(
        ['defaults', 'write', 'com.apple.dock', 'memorizedTilesize', '-float', str(cur_size)],
        check=True,
        stderr=subprocess.DEVNULL,
        stdout=subprocess.DEVNULL)
    print("saved the current dock size: %d%%" % int(cur_size * 100))

def restore_dock_size():
    try:
        result = subprocess.run(
            ['defaults', 'read', 'com.apple.dock', 'memorizedTilesize'],
            check=True,
            stderr=subprocess.DEVNULL,
            stdout=subprocess.PIPE)
        memorized_size = float(result.stdout.decode().strip())
        set_size_func = hi_dll.CoreDockSetTileSize
        set_size_func.argtypes = [ctypes.c_float]
        set_size_func(ctypes.c_float(memorized_size))
        print("restored the memorized dock size: %d%%" % int(memorized_size * 100))
    except subprocess.CalledProcessError:
        print("error: no memorized dock size")
        sys.exit(1)

parser = argparse.ArgumentParser(
    prog='dock-memory',
    description='A program that memorizes your dock size')
action_group = parser.add_mutually_exclusive_group()
action_group.add_argument('-s', action='store_true', help='Save the current dock size')
action_group.add_argument('-r', action='store_true', help='Restore the saved dock size')
args = parser.parse_args()

if args.s:
    save_dock_size()
elif args.r:
    restore_dock_size()
else:
    print('error: one of the arguments -s or -r is required')
    sys.exit(1)