Arrow

You can escape regular expressions by enclosing them in square brackets []. This is useful for parsing strings with unpredictable whitespace or separators (e.g., log files).

>>> fmt = r"ddd[\s+]MMM[\s+]DD[\s+]HH:mm:ss[\s+]YYYY"
>>> arrow.get("Mon Sep 08 16:41:45 2014", fmt)
<Arrow [2014-09-08T16:41:45+00:00]>

>>> arrow.get("Mon \tSep 08   16:41:45     2014", fmt)
<Arrow [2014-09-08T16:41:45+00:00]>

To include literal text, tokens, or phrases in your format string without them being interpreted as date components, enclose them in square brackets [].

>>> fmt = "YYYY-MM-DD h [h] m"
>>> arw = arrow.get("2018-03-09 8 h 40", fmt)
<Arrow [2018-03-09T08:40:00+00:00]>
>>> arw.format(fmt)
'2018-03-09 8 h 40'

>>> fmt = "YYYY-MM-DD h [hello] m"
>>> arw = arrow.get("2018-03-09 8 hello 40", fmt)
<Arrow [2018-03-09T08:40:00+00:00]>
>>> arw.format(fmt)
'2018-03-09 8 hello 40'

To install the Arrow library, use pip or pipenv to add it to your environment.

$ pip install -U arrow

When using arrow.get(), you can pass the normalize_whitespace=True flag to automatically handle redundant spaces, tabs, or newlines in the input string.

>>> arrow.get('\t \n  2013-05-05T12:30:45.123456 \t \n', normalize_whitespace=True)
<Arrow [2013-05-05T12:30:45.123456+00:00]>

>>> arrow.get('2013-05-05  T \n   12:30:45\t123456', 'YYYY-MM-DD T HH:mm:ss S', normalize_whitespace=True)
<Arrow [2013-05-05T12:30:45+00:00]>

You can create Arrow objects using several methods:

• Current time: Use arrow.utcnow() for UTC or arrow.now() for local time. You can specify a timezone with arrow.now('US/Pacific').
• Timestamps: Use arrow.get() with an int or float timestamp.
• Datetime objects: Pass a datetime object to arrow.get(). You can also provide a timezone string or a tzinfo object.
• Strings: Use arrow.get() with a format string for custom patterns, or pass ISO 8601 compliant strings directly. arrow.get() can also search for dates within a larger string.
• Direct instantiation: Use arrow.get(year, month, day) or arrow.Arrow(year, month, day) with arguments similar to the standard datetime constructor.

Arrow can parse date strings that are surrounded by punctuation characters such as , . ; : ? ! " ' [ ] { } ( ) < >`. However, be careful: if multiple punctuation marks follow the date, it may raise an exception.

>>> arrow.get("Cool date: 2019-10-31T09:12:45.123456+04:30.", "YYYY-MM-DDTHH:mm:ss.SZZ")
<Arrow [2019-10-31T09:12:45.123456+04:30]>

>>> arrow.get("Tomorrow (2019-10-31) is Halloween!", "YYYY-MM-DD")
<Arrow [2019-10-31T00:00:00+00:00]>

Arrow objects are immutable; these methods return a new Arrow object:

• .replace(): Create a new object with altered attributes (e.g., hour, minute) or a different timezone via tzinfo.
• .shift(): Create a new object by moving time forward or backward using units like weeks, days, hours, etc. (e.g., arw.shift(weeks=+3)).
• Ambiguous times: Use .replace(fold=1) to move between the earlier and later moments of an ambiguous time during a timezone transition.