| # Copyright 2021 gRPC authors. |
| # |
| # Licensed under the Apache License, Version 2.0 (the "License"); |
| # you may not use this file except in compliance with the License. |
| # You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| """This contains common helpers for working with dates and time.""" |
| import datetime |
| import re |
| from typing import Pattern |
| |
| RE_ZERO_OFFSET: Pattern[str] = re.compile(r'[+\-]00:?00$') |
| |
| |
| def utc_now() -> datetime.datetime: |
| """Construct a datetime from current time in UTC timezone.""" |
| return datetime.datetime.now(datetime.timezone.utc) |
| |
| |
| def shorten_utc_zone(utc_datetime_str: str) -> str: |
| """Replace ±00:00 timezone designator with Z (zero offset AKA Zulu time).""" |
| return RE_ZERO_OFFSET.sub('Z', utc_datetime_str) |
| |
| |
| def iso8601_utc_time(time: datetime.datetime = None) -> str: |
| """Converts datetime UTC and formats as ISO-8601 Zulu time.""" |
| utc_time = time.astimezone(tz=datetime.timezone.utc) |
| return shorten_utc_zone(utc_time.isoformat()) |
| |
| |
| def datetime_suffix(*, seconds: bool = False) -> str: |
| """Return current UTC date, and time in a format useful for resource naming. |
| |
| Examples: |
| - 20210626-1859 (seconds=False) |
| - 20210626-185942 (seconds=True) |
| Use in resources names incompatible with ISO 8601, e.g. some GCP resources |
| that only allow lowercase alphanumeric chars and dashes. |
| |
| Hours and minutes are joined together for better readability, so time is |
| visually distinct from dash-separated date. |
| """ |
| return utc_now().strftime('%Y%m%d-%H%M' + ('%S' if seconds else '')) |