1import re
  2
  3class Singleton(type):
  4
  5    _instances = {}
  6
  7    def __call__(cls, *args, **kwargs):
  8        if cls not in cls._instances:
  9            cls._instances[cls] = super().__call__(*args, **kwargs)
 10        return cls._instances[cls]
 11    
 12
 13class Santa(metaclass=Singleton):
 14
 15    _presents = {}
 16
 17    def __init__(self):
 18        pass
 19
 20    def __call__(self, kid, message):
 21        wish = re.search(r'(?<=(["\']))(\s*\w*)+(?=\1)', message).group()
 22        self._presents[kid] = wish
 23
 24    def __matmul__(self, letter):
 25        signature = re.search(r'^\s*\d+\s*$', letter, re.M).group()
 26        wish = re.search(r'(?<=(["\']))(\s*\w*)+(?=\1)', letter).group()
 27        for kid in self._presents.keys(): 
 28            if str(id(kid)) == signature:
 29                self._presents[kid] = wish
 30                break
 31
 32    def __iter__(self):
 33        return iter(self._presents.values())
 34    
 35    def _find_most_popular_present(self):
 36        presents_popularity = {}
 37        for present in self._presents.values():
 38            if present:
 39                val = presents_popularity.get(present, 0)
 40                presents_popularity[present] = val + 1
 41        if presents_popularity:
 42            return max(presents_popularity, key=presents_popularity.get)
 43        else:
 44            return -1
 45
 46    def xmas(self):
 47        self._presents = {kid : present for kid, present in self._presents.items() if kid.age < 5}
 48        most_popular = self._find_most_popular_present()
 49        if most_popular == -1:
 50            for kid in self._presents.keys():
 51                kid.age_up() # тъпо е да е тук, но уви
 52            return
 53        for kid, present in self._presents.items():
 54            if kid.is_bad():
 55                kid('coal')
 56            else:
 57                if present:
 58                    kid(present)
 59                else:
 60                    kid(most_popular)
 61            kid.age_up()
 62        self._presents = {kid : None for kid in self._presents.keys()}
 63    
 64    def add_kid(self, kid):
 65        self._presents[kid] = None
 66
 67
 68class Kid(type):
 69
 70    _santa = Santa()
 71
 72    def _exception_decorator(func):
 73        def decorated(self, *args, **kwargs):
 74            try:
 75                return func(self, *args, **kwargs)
 76            except Exception:
 77                self._has_thrown_exception = True
 78                raise
 79        return decorated
 80
 81    def _age_up(kid):
 82        kid.age += 1
 83        kid._has_thrown_exception = False
 84
 85    def __new__(cls, name, bases, attr_dict):
 86        if '__call__' not in attr_dict:
 87            raise NotImplementedError
 88        attr_dict['_has_thrown_exception'] = False
 89        attr_dict['age'] = 0
 90        attr_dict['age_up'] = lambda self: cls._age_up(self)
 91        attr_dict['is_bad'] = lambda self: self._has_thrown_exception
 92
 93        for attr, value in attr_dict.items():
 94            if not attr.startswith('_') and callable(value):
 95                attr_dict[attr] = cls._exception_decorator(value)
 96        return type.__new__(cls, name, bases, attr_dict)
 97    
 98    def __call__(cls, *args, **kwds):
 99        obj = super().__call__(*args, **kwds)
100        cls._santa.add_kid(obj)
101        return obj