def log(text = ""):
	def decorator(fn):
		@functools.wraps(fn)
		def wrapper(*args, **kw):
			if text != "":
				print('%s %s():' % (text, fn.__name__))
			else:
				print('%s():' % fn.__name__)
			print("begin call")
			fn(*args, **kw)
			print("end call")
			return fn(*args, **kw)
		return wrapper
	return decorator