Иногда нужно выполнить блок кода с несколькими менеджерами контекста:
with open('f') as f: with open('g') as g: with open('h') as h: pass
Начиная с Python 2.7 и 3.1, это можно записать в одной конструкции with:
o = open with o('f') as f, o('g') as g, o('h') as h: pass
Раньше для этого использовали функцию contextlib.nested:
with nested(o('f'), o('g'), o('h')) as (f, g, h): pass
Если же число менеджеров контекста заранее неизвестно, лучше подойдёт более продвинутый инструмент. contextlib.ExitStack позволяет открывать любое число контекстов в произвольный момент, но гарантирует корректный выход из них в конце:
with ExitStack() as stack: f = stack.enter_context(o('f')) g = stack.enter_context(o('g')) other = [ stack.enter_context(o(filename)) for filename in filenames ]
Иногда нужно выполнить блок кода с несколькими менеджерами контекста:
with open('f') as f: with open('g') as g: with open('h') as h: pass
Начиная с Python 2.7 и 3.1, это можно записать в одной конструкции with:
o = open with o('f') as f, o('g') as g, o('h') as h: pass
Раньше для этого использовали функцию contextlib.nested:
with nested(o('f'), o('g'), o('h')) as (f, g, h): pass
Если же число менеджеров контекста заранее неизвестно, лучше подойдёт более продвинутый инструмент. contextlib.ExitStack позволяет открывать любое число контекстов в произвольный момент, но гарантирует корректный выход из них в конце:
with ExitStack() as stack: f = stack.enter_context(o('f')) g = stack.enter_context(o('g')) other = [ stack.enter_context(o(filename)) for filename in filenames ]
Bitcoin is a decentralized digital currency that you can buy, sell and exchange directly, without an intermediary like a bank. Bitcoin’s creator, Satoshi Nakamoto, originally described the need for “an electronic payment system based on cryptographic proof instead of trust.” Each and every Bitcoin transaction that’s ever been made exists on a public ledger accessible to everyone, making transactions hard to reverse and difficult to fake. That’s by design: Core to their decentralized nature, Bitcoins aren’t backed by the government or any issuing institution, and there’s nothing to guarantee their value besides the proof baked in the heart of the system. “The reason why it’s worth money is simply because we, as people, decided it has value—same as gold,” says Anton Mozgovoy, co-founder & CEO of digital financial service company Holyheld.
At a time when the Indian stock market is peaking and has rallied immensely compared to global markets, there are companies that have not performed in the last 10 years. These are definitely a minor portion of the market considering there are hundreds of stocks that have turned multibagger since 2020. What went wrong with these stocks? Reasons vary from corporate governance, sectoral weakness, company specific and so on. But the more important question is, are these stocks worth buying?
