pendulum why ? (timezone-aware datetimes)

Why Pendulum ?

Native datetime instances are enough for basic cases but when you face more complex use-cases they often show limitations and are not so intuitive to work with.

Pendulum provides a cleaner and more easy to use API while still relying on the standard library. So it’s still datetime but better .

Unlike other datetime libraries for Python, Pendulum is a drop-in replacement for the standard datetime class (it inherits from it), so, basically, you can replace all your datetime instances by DateTime instances in you code (exceptions exist for libraries that check the type of the objects by using the type function like sqlite3 or PyMySQL for instance).

It also removes the notion of naive datetimes : each Pendulum instance is timezone-aware and by default in UTC for ease of use.

Pendulum also improves the standard timedelta class by providing more intuitive methods and properties.

Display “YYYY-MM-DD”

In [1]: import pendulum
In [2]: print("Europe/Paris").format("YYYY-MM-DD"))

Display in french with milliseconds

>>> print("Europe/Paris").format("dddd DD MMMM YYYY HH:mm:ss:SSS", locale="fr"))
jeudi 16 février 2023 16:10:01:323

Display YYY-MM-DD with milliseconds

>>> print("Europe/Paris").format("YYYY-MM-DD HH:mm:ss:SSS"))
2023-02-16 16:12:43:864

Display diff time

begin: pendulum.DateTime = None

def log_request(request):
    global begin
    begin ="Europe/Paris")
    begin_str = begin.format("HH:mm:ss:SSS")
        f"\nRequest event hook:\n{begin_str} {request.method} {request.url}\nheaders:{request.headers}\nWaiting for response"

def log_response(response):
    end ="Europe/Paris")
    end_str = end.format("HH:mm:ss:SSS")
    diff = end - begin
    milliseconds = diff.microseconds/1000
    request = response.request
        f"\nResponse event hook:\n{end_str} (in {milliseconds} ms) {request.method} {request.url}\nStatus:{response.status_code}\n"
>>> begin ="Europe/Paris")
>>> end ="Europe/Paris")
>>> diff = end - begin
>>> diff.
diff.as_interval()      diff.hours              diff.in_months()        diff.in_years()         diff.min                diff.remaining_days     diff.start              diff.total_seconds(
diff.as_timedelta()     diff.in_days()          diff.in_seconds()       diff.invert             diff.minutes            diff.remaining_seconds  diff.total_days()       diff.total_weeks()
diff.days               diff.in_hours()         diff.in_weeks()         diff.max                diff.months             diff.resolution         diff.total_hours()      diff.weeks
diff.end                diff.in_minutes()       diff.in_words(          diff.microseconds       diff.range(             diff.seconds            diff.total_minutes()    diff.years