ChainMap последовательно просматривает все вложенные отображения и возвращает первое найденное значение. Однако все операции изменения затрагивают только первое отображение:
d = ChainMap(dict(a=1), dict(a=2, b=2)) d['c'] = 3 d # ChainMap({'a': 1, 'c': 3}, {'a': 2, 'b': 2})
ChainMap последовательно просматривает все вложенные отображения и возвращает первое найденное значение. Однако все операции изменения затрагивают только первое отображение:
d = ChainMap(dict(a=1), dict(a=2, b=2)) d['c'] = 3 d # ChainMap({'a': 1, 'c': 3}, {'a': 2, 'b': 2})
Bitcoin mining is the process of adding new transactions to the Bitcoin blockchain. It’s a tough job. People who choose to mine Bitcoin use a process called proof of work, deploying computers in a race to solve mathematical puzzles that verify transactions.To entice miners to keep racing to solve the puzzles and support the overall system, the Bitcoin code rewards miners with new Bitcoins. “This is how new coins are created” and new transactions are added to the blockchain, says Okoro.
The Singapore stock market has alternated between positive and negative finishes through the last five trading days since the end of the two-day winning streak in which it had added more than a dozen points or 0.4 percent. The Straits Times Index now sits just above the 3,060-point plateau and it's likely to see a narrow trading range on Monday.
