Caching to file with a decorator

cache_to_file.py

def cache_to_file(file_name):
	def decorator(f):
		try:
			cache = json.load(open(file_name, 'r'))
		except (IOError, ValueError):
			cache = {}
		def new_func(*args, **kwargs):
			cache.update({ps:f(*args,**kwargs)}) if (ps := param_string(args, kwargs)) not in cache else (json.dump(cache, open(file_name, 'w')))
			return cache[ps]
		return new_func
	return decorator

@cache_to_file('rank_cache.json')
def rank(a, b):
	print(f'\nA: {a}\nB: {b}')
	choice = None
	while not choice or not (csu := choice.strip().upper()) in {'A','B'}:
		choice = input('Which is better, A or B? [A/B] ')
	if csu == 'A':
		return 1 # A > B
	elif csu == 'B':
		return -1 # A < B