29fafe26eb
* fix parse * Revert "fix parse" This reverts commit3c76c5a782. * fix parse timestamp * extract datetime parser * remove print * use parser * top level docstring * rename variable * do not use timestamp() * Revert "do not use timestamp()" This reverts commit016cb69193. * update comment * bump cdk version * Update template
39 lines
1.7 KiB
Python
39 lines
1.7 KiB
Python
#
|
|
# Copyright (c) 2022 Airbyte, Inc., all rights reserved.
|
|
#
|
|
|
|
import datetime
|
|
from typing import Union
|
|
|
|
|
|
class DatetimeParser:
|
|
"""
|
|
Parses and formats datetime objects according to a specified format.
|
|
|
|
This class mainly acts as a wrapper to properly handling timestamp formatting through the "%s" directive.
|
|
|
|
%s is part of the list of format codes required by the 1989 C standard, but it is unreliable because it always return a datetime in the system's timezone.
|
|
Instead of using the directive directly, we can use datetime.fromtimestamp and dt.timestamp()
|
|
"""
|
|
|
|
def parse(self, date: Union[str, int], format: str, timezone):
|
|
# "%s" is a valid (but unreliable) directive for formatting, but not for parsing
|
|
# It is defined as
|
|
# The number of seconds since the Epoch, 1970-01-01 00:00:00+0000 (UTC). https://man7.org/linux/man-pages/man3/strptime.3.html
|
|
#
|
|
# The recommended way to parse a date from its timestamp representation is to use datetime.fromtimestamp
|
|
# See https://stackoverflow.com/a/4974930
|
|
if format == "%s":
|
|
return datetime.datetime.fromtimestamp(int(date), tz=timezone)
|
|
else:
|
|
return datetime.datetime.strptime(str(date), format).replace(tzinfo=timezone)
|
|
|
|
def format(self, dt: datetime.datetime, format: str) -> str:
|
|
# strftime("%s") is unreliable because it ignores the time zone information and assumes the time zone of the system it's running on
|
|
# It's safer to use the timestamp() method than the %s directive
|
|
# See https://stackoverflow.com/a/4974930
|
|
if format == "%s":
|
|
return str(int(dt.timestamp()))
|
|
else:
|
|
return dt.strftime(format)
|