From d6d80a17444c90259c5bfdacb84c61e6bfece655 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 5 Jan 2023 11:38:41 +0100 Subject: Merging upstream version 3.0.0~a1. Signed-off-by: Daniel Baumann --- README.rst | 400 +++++++++++++++++++++++++++---------------------------------- 1 file changed, 176 insertions(+), 224 deletions(-) (limited to 'README.rst') diff --git a/README.rst b/README.rst index d65fb47..78437e2 100644 --- a/README.rst +++ b/README.rst @@ -1,224 +1,176 @@ -Pendulum -######## - -.. image:: https://img.shields.io/pypi/v/pendulum.svg - :target: https://pypi.python.org/pypi/pendulum - -.. image:: https://img.shields.io/pypi/l/pendulum.svg - :target: https://pypi.python.org/pypi/pendulum - -.. image:: https://img.shields.io/codecov/c/github/sdispater/pendulum/master.svg - :target: https://codecov.io/gh/sdispater/pendulum/branch/master - -.. image:: https://travis-ci.org/sdispater/pendulum.svg - :alt: Pendulum Build status - :target: https://travis-ci.org/sdispater/pendulum - -Python datetimes made easy. - -Supports Python **2.7** and **3.4+**. - - -.. code-block:: python - - >>> import pendulum - - >>> now_in_paris = pendulum.now('Europe/Paris') - >>> now_in_paris - '2016-07-04T00:49:58.502116+02:00' - - # Seamless timezone switching - >>> now_in_paris.in_timezone('UTC') - '2016-07-03T22:49:58.502116+00:00' - - >>> tomorrow = pendulum.now().add(days=1) - >>> last_week = pendulum.now().subtract(weeks=1) - - >>> past = pendulum.now().subtract(minutes=2) - >>> past.diff_for_humans() - >>> '2 minutes ago' - - >>> delta = past - last_week - >>> delta.hours - 23 - >>> delta.in_words(locale='en') - '6 days 23 hours 58 minutes' - - # Proper handling of datetime normalization - >>> pendulum.datetime(2013, 3, 31, 2, 30, tz='Europe/Paris') - '2013-03-31T03:30:00+02:00' # 2:30 does not exist (Skipped time) - - # Proper handling of dst transitions - >>> just_before = pendulum.datetime(2013, 3, 31, 1, 59, 59, 999999, tz='Europe/Paris') - '2013-03-31T01:59:59.999999+01:00' - >>> just_before.add(microseconds=1) - '2013-03-31T03:00:00+02:00' - - -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. - - -Why not Arrow? -============== - -Arrow is the most popular datetime library for Python right now, however its behavior -and API can be erratic and unpredictable. The ``get()`` method can receive pretty much anything -and it will try its best to return something while silently failing to handle some cases: - -.. code-block:: python - - arrow.get('2016-1-17') - # - - pendulum.parse('2016-1-17') - # - - arrow.get('20160413') - # - - pendulum.parse('20160413') - # - - arrow.get('2016-W07-5') - # - - pendulum.parse('2016-W07-5') - # - - # Working with DST - just_before = arrow.Arrow(2013, 3, 31, 1, 59, 59, 999999, 'Europe/Paris') - just_after = just_before.replace(microseconds=1) - '2013-03-31T02:00:00+02:00' - # Should be 2013-03-31T03:00:00+02:00 - - (just_after.to('utc') - just_before.to('utc')).total_seconds() - -3599.999999 - # Should be 1e-06 - - just_before = pendulum.datetime(2013, 3, 31, 1, 59, 59, 999999, 'Europe/Paris') - just_after = just_before.add(microseconds=1) - '2013-03-31T03:00:00+02:00' - - (just_after.in_timezone('utc') - just_before.in_timezone('utc')).total_seconds() - 1e-06 - -Those are a few examples showing that Arrow cannot always be trusted to have a consistent -behavior with the data you are passing to it. - - -Limitations -=========== - -Even though the ``DateTime`` class is a subclass of ``datetime`` there are some rare cases where -it can't replace the native class directly. Here is a list (non-exhaustive) of the reported cases with -a possible solution, if any: - -* ``sqlite3`` will use the ``type()`` function to determine the type of the object by default. To work around it you can register a new adapter: - -.. code-block:: python - - from pendulum import DateTime - from sqlite3 import register_adapter - - register_adapter(DateTime, lambda val: val.isoformat(' ')) - -* ``mysqlclient`` (former ``MySQLdb``) and ``PyMySQL`` will use the ``type()`` function to determine the type of the object by default. To work around it you can register a new adapter: - -.. code-block:: python - - import MySQLdb.converters - import pymysql.converters - - from pendulum import DateTime - - MySQLdb.converters.conversions[DateTime] = MySQLdb.converters.DateTime2literal - pymysql.converters.conversions[DateTime] = pymysql.converters.escape_datetime - -* ``django`` will use the ``isoformat()`` method to store datetimes in the database. However since ``pendulum`` is always timezone aware the offset information will always be returned by ``isoformat()`` raising an error, at least for MySQL databases. To work around it you can either create your own ``DateTimeField`` or use the previous workaround for ``MySQLdb``: - -.. code-block:: python - - from django.db.models import DateTimeField as BaseDateTimeField - from pendulum import DateTime - - - class DateTimeField(BaseDateTimeField): - - def value_to_string(self, obj): - val = self.value_from_object(obj) - - if isinstance(value, DateTime): - return value.to_datetime_string() - - return '' if val is None else val.isoformat() - - -Resources -========= - -* `Official Website `_ -* `Documentation `_ -* `Issue Tracker `_ - - -Contributing -============ - -Contributions are welcome, especially with localization. - -Getting started ---------------- - -To work on the Pendulum codebase, you'll want to clone the project locally -and install the required depedendencies via `poetry `_. - -.. code-block:: bash - - $ git clone git@github.com:sdispater/pendulum.git - $ poetry install - -Localization ------------- - -If you want to help with localization, there are two different cases: the locale already exists -or not. - -If the locale does not exist you will need to create it by using the ``clock`` utility: - -.. code-block:: bash - - ./clock locale create - -It will generate a directory in ``pendulum/locales`` named after your locale, with the following -structure: - -.. code-block:: text - - / - - custom.py - - locale.py - -The ``locale.py`` file must not be modified. It contains the translations provided by -the CLDR database. - -The ``custom.py`` file is the one you want to modify. It contains the data needed -by Pendulum that are not provided by the CLDR database. You can take the `en `_ -data as a reference to see which data is needed. - -You should also add tests for the created or modified locale. +Pendulum +######## + +.. image:: https://img.shields.io/pypi/v/pendulum.svg + :target: https://pypi.python.org/pypi/pendulum + +.. image:: https://img.shields.io/pypi/l/pendulum.svg + :target: https://pypi.python.org/pypi/pendulum + +.. image:: https://img.shields.io/codecov/c/github/sdispater/pendulum/master.svg + :target: https://codecov.io/gh/sdispater/pendulum/branch/master + +.. image:: https://github.com/sdispater/pendulum/actions/workflows/tests.yml/badge.svg + :alt: Pendulum Build status + :target: https://github.com/sdispater/pendulum/actions + + +Python datetimes made easy. + +Supports Python **2.7** and **3.4+**. + + +.. code-block:: python + + >>> import pendulum + + >>> now_in_paris = pendulum.now('Europe/Paris') + >>> now_in_paris + '2016-07-04T00:49:58.502116+02:00' + + # Seamless timezone switching + >>> now_in_paris.in_timezone('UTC') + '2016-07-03T22:49:58.502116+00:00' + + >>> tomorrow = pendulum.now().add(days=1) + >>> last_week = pendulum.now().subtract(weeks=1) + + >>> past = pendulum.now().subtract(minutes=2) + >>> past.diff_for_humans() + '2 minutes ago' + + >>> delta = past - last_week + >>> delta.hours + 23 + >>> delta.in_words(locale='en') + '6 days 23 hours 58 minutes' + + # Proper handling of datetime normalization + >>> pendulum.datetime(2013, 3, 31, 2, 30, tz='Europe/Paris') + '2013-03-31T03:30:00+02:00' # 2:30 does not exist (Skipped time) + + # Proper handling of dst transitions + >>> just_before = pendulum.datetime(2013, 3, 31, 1, 59, 59, 999999, tz='Europe/Paris') + '2013-03-31T01:59:59.999999+01:00' + >>> just_before.add(microseconds=1) + '2013-03-31T03:00:00+02:00' + + +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. + +Limitations +=========== + +Even though the ``DateTime`` class is a subclass of ``datetime`` there are some rare cases where +it can't replace the native class directly. Here is a list (non-exhaustive) of the reported cases with +a possible solution, if any: + +* ``sqlite3`` will use the ``type()`` function to determine the type of the object by default. To work around it you can register a new adapter: + +.. code-block:: python + + from pendulum import DateTime + from sqlite3 import register_adapter + + register_adapter(DateTime, lambda val: val.isoformat(' ')) + +* ``mysqlclient`` (former ``MySQLdb``) and ``PyMySQL`` will use the ``type()`` function to determine the type of the object by default. To work around it you can register a new adapter: + +.. code-block:: python + + import MySQLdb.converters + import pymysql.converters + + from pendulum import DateTime + + MySQLdb.converters.conversions[DateTime] = MySQLdb.converters.DateTime2literal + pymysql.converters.conversions[DateTime] = pymysql.converters.escape_datetime + +* ``django`` will use the ``isoformat()`` method to store datetimes in the database. However since ``pendulum`` is always timezone aware the offset information will always be returned by ``isoformat()`` raising an error, at least for MySQL databases. To work around it you can either create your own ``DateTimeField`` or use the previous workaround for ``MySQLdb``: + +.. code-block:: python + + from django.db.models import DateTimeField as BaseDateTimeField + from pendulum import DateTime + + + class DateTimeField(BaseDateTimeField): + + def value_to_string(self, obj): + val = self.value_from_object(obj) + + if isinstance(value, DateTime): + return value.to_datetime_string() + + return '' if val is None else val.isoformat() + + +Resources +========= + +* `Official Website `_ +* `Documentation `_ +* `Issue Tracker `_ + + +Contributing +============ + +Contributions are welcome, especially with localization. + +Getting started +--------------- + +To work on the Pendulum codebase, you'll want to clone the project locally +and install the required dependencies via `poetry `_. + +.. code-block:: bash + + $ git clone git@github.com:sdispater/pendulum.git + $ poetry install + +Localization +------------ + +If you want to help with localization, there are two different cases: the locale already exists +or not. + +If the locale does not exist you will need to create it by using the ``clock`` utility: + +.. code-block:: bash + + ./clock locale create + +It will generate a directory in ``pendulum/locales`` named after your locale, with the following +structure: + +.. code-block:: text + + / + - custom.py + - locale.py + +The ``locale.py`` file must not be modified. It contains the translations provided by +the CLDR database. + +The ``custom.py`` file is the one you want to modify. It contains the data needed +by Pendulum that are not provided by the CLDR database. You can take the `en `_ +data as a reference to see which data is needed. + +You should also add tests for the created or modified locale. -- cgit v1.2.3