from functools import reduce
common_keys = reduce(op.and_, (list(d.keys()) for d in my_dicts))
common_items = {}
for key in common_keys:
    value = my_dicts[0][key]
if all(d[key] == value for d in my_dicts):
    common_items[key] = value
Найти уникальную пару (ключ: значение) с учетом N словарей в python