attotimebuilder 0.4.2

A library for using the attotime datetime API with aniso8601

AttoTimeBuilder

aniso8601 builder for attodatetimes

Features

• Provides AttoTimeBuilder compatible with aniso8601

• Returns attodatetime and attotimedelta types

Installation

The recommended installation method is to use pip:

$ pip install attotimebuilder

Alternatively, you can download the source (git repository hosted at Codeberg) and install directly:

$ python setup.py install

Use

Parsing datetimes

To parse a typical ISO 8601 datetime string:

>>> import aniso8601
>>> from attotimebuilder import AttoTimeBuilder
>>> aniso8601.parse_datetime('1977-06-10T12:00:00', builder=AttoTimeBuilder)
attotime.attodatetime(1977, 6, 10, 12, 0, 0, 0, 0)

Alternative delimiters can be specified, for example, a space:

>>> aniso8601.parse_datetime('1977-06-10 12:00:00', delimiter=' ', builder=AttoTimeBuilder)
attotime.attodatetime(1977, 6, 10, 12, 0, 0, 0, 0)

Both UTC (Z) and UTC offsets for timezones are supported:

>>> aniso8601.parse_datetime('1977-06-10T12:00:00Z', builder=AttoTimeBuilder)
attotime.attodatetime(1977, 6, 10, 12, 0, 0, 0, 0, +0:00:00 UTC)
>>> aniso8601.parse_datetime('1979-06-05T08:00:00-08:00', builder=AttoTimeBuilder)
attotime.attodatetime(1979, 6, 5, 8, 0, 0, 0, 0, -8:00:00 UTC)

Leap seconds are explicitly not supported:

>>> aniso8601.parse_datetime('2018-03-06T23:59:60', builder=AttoTimeBuilder)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/nielsenb/Jetfuse/attotimebuilder/python2/lib/python2.7/site-packages/aniso8601/time.py", line 131, in parse_datetime
    return builder.build_datetime(datepart, timepart)
  File "attotimebuilder/__init__.py", line 120, in build_datetime
    cls._build_object(time))
  File "/home/nielsenb/Jetfuse/attotimebuilder/python2/lib/python2.7/site-packages/aniso8601/builder.py", line 71, in _build_object
    ss=parsetuple[2], tz=parsetuple[3])
  File "attotimebuilder/__init__.py", line 73, in build_time
    raise LeapSecondError('Leap seconds are not supported.')
aniso8601.exceptions.LeapSecondError: Leap seconds are not supported.

Parsing dates

There is no attodate type, so native Python datetime.date objects are returned.

To parse a date represented in an ISO 8601 string:

>>> import aniso8601
>>> from attotimebuilder import AttoTimeBuilder
>>> aniso8601.parse_date('1984-04-23', builder=AttoTimeBuilder)
datetime.date(1984, 4, 23)

Basic format is supported as well:

>>> aniso8601.parse_date('19840423', builder=AttoTimeBuilder)
datetime.date(1984, 4, 23)

To parse a date using the ISO 8601 week date format:

>>> aniso8601.parse_date('1986-W38-1', builder=AttoTimeBuilder)
datetime.date(1986, 9, 15)

To parse an ISO 8601 ordinal date:

>>> aniso8601.parse_date('1988-132', builder=AttoTimeBuilder)
datetime.date(1988, 5, 11)

Parsing times

To parse a time formatted as an ISO 8601 string:

>>> import aniso8601
>>> from attotimebuilder import AttoTimeBuilder
>>> aniso8601.parse_time('11:31:14', builder=AttoTimeBuilder)
attotime.attotime(11, 31, 14, 0, 0)

As with all of the above, basic format is supported:

>>> aniso8601.parse_time('113114', builder=AttoTimeBuilder)
attotime.attotime(11, 31, 14, 0, 0)

A UTC offset can be specified for times:

>>> aniso8601.parse_time('17:18:19-02:30', builder=AttoTimeBuilder)
attotime.attotime(17, 18, 19, 0, 0, -2:30:00 UTC)
>>> aniso8601.parse_time('171819Z', builder=AttoTimeBuilder)
attotime.attotime(17, 18, 19, 0, 0, +0:00:00 UTC)

Reduced accuracy is supported:

>>> aniso8601.parse_time('21:42', builder=AttoTimeBuilder)
attotime.attotime(21, 42, 0, 0, 0)
>>> aniso8601.parse_time('22', builder=AttoTimeBuilder)
attotime.attotime(22, 0, 0, 0, 0)

A decimal fraction is always allowed on the lowest order element of an ISO 8601 formatted time:

>>> aniso8601.parse_time('22:33.5', builder=AttoTimeBuilder)
attotime.attotime(22, 33, 30, 0, 0.0)
>>> aniso8601.parse_time('23.75', builder=AttoTimeBuilder)
attotime.attotime(23, 45, 0, 0, 0.00)

Leap seconds are explicitly not supported and attempting to parse one raises a LeapSecondError:

>>> aniso8601.parse_time('23:59:60', builder=AttoTimeBuilder)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/nielsenb/Jetfuse/attotimebuilder/python2/lib/python2.7/site-packages/aniso8601/time.py", line 116, in parse_time
    return _RESOLUTION_MAP[get_time_resolution(timestr)](timestr, tz, builder)
  File "/home/nielsenb/Jetfuse/attotimebuilder/python2/lib/python2.7/site-packages/aniso8601/time.py", line 165, in _parse_second_time
    return builder.build_time(hh=hourstr, mm=minutestr, ss=secondstr, tz=tz)
  File "attotimebuilder/__init__.py", line 73, in build_time
    raise LeapSecondError('Leap seconds are not supported.')
aniso8601.exceptions.LeapSecondError: Leap seconds are not supported.

Parsing durations

To parse a duration formatted as an ISO 8601 string:

>>> import aniso8601
>>> from attotimebuilder import AttoTimeBuilder
>>> aniso8601.parse_duration('P1Y2M3DT4H54M6S', builder=AttoTimeBuilder)
attotime.attotimedelta(428, 17646)

Reduced accuracy is supported:

>>> aniso8601.parse_duration('P1Y', builder=AttoTimeBuilder)
attotime.attotimedelta(365)

A decimal fraction is allowed on the lowest order element:

>>> aniso8601.parse_duration('P1YT3.5M', builder=AttoTimeBuilder)
attotime.attotimedelta(365, 210)

The decimal fraction can be specified with a comma instead of a full-stop:

>>> aniso8601.parse_duration('P1YT3,5M', builder=AttoTimeBuilder)
attotime.attotimedelta(365, 210)

Parsing a duration from a combined date and time is supported as well:

>>> aniso8601.parse_duration('P0001-01-02T01:30:5', builder=AttoTimeBuilder)
attotime.attotimedelta(397, 5405)

Parsing intervals

To parse an interval specified by a start and end:

>>> import aniso8601
>>> from attotimebuilder import AttoTimeBuilder
>>> aniso8601.parse_interval('2007-03-01T13:00:00/2008-05-11T15:30:00', builder=AttoTimeBuilder)
(attotime.attodatetime(2007, 3, 1, 13, 0, 0, 0, 0), attotime.attodatetime(2008, 5, 11, 15, 30, 0, 0, 0))

Intervals specified by a start time and a duration are supported:

>>> aniso8601.parse_interval('2007-03-01T13:00:00/P1Y2M10DT2H30M', builder=AttoTimeBuilder)
(attotime.attodatetime(2007, 3, 1, 13, 0, 0, 0, 0), attotime.attodatetime(2008, 5, 9, 15, 30, 0, 0, 0))

A duration can also be specified by a duration and end time, note that no attodate type exists, so dates are returned as native datetime.date objects:

>>> aniso8601.parse_interval('P1M/1981-04-05', builder=AttoTimeBuilder)
(datetime.date(1981, 4, 5), datetime.date(1981, 3, 6))

Notice that the result of the above parse is not in order from earliest to latest. If sorted intervals are required, simply use the sorted keyword as shown below:

>>> sorted(aniso8601.parse_interval('P1M/1981-04-05', builder=AttoTimeBuilder))
[datetime.date(1981, 3, 6), datetime.date(1981, 4, 5)]

The end of an interval is returned as a attodatetime when required to maintain the resolution specified by a duration, even if the duration start is given as a date:

>>> aniso8601.parse_interval('2014-11-12/PT4H54M6.5S', builder=AttoTimeBuilder)
(datetime.date(2014, 11, 12), attotime.attodatetime(2014, 11, 12, 4, 54, 6, 500000, 0.0))
>>> aniso8601.parse_interval('2007-03-01/P1.5D', builder=AttoTimeBuilder)
(datetime.date(2007, 3, 1), attotime.objects.attodatetime(2007, 3, 2, 12, 0, 0, 0, 0.0))

Repeating intervals are supported as well, and return a generator:

>>> aniso8601.parse_repeating_interval('R3/1981-04-05/P1D', builder=AttoTimeBuilder)
<generator object _date_generator at 0x7fba29feed20>
>>> list(aniso8601.parse_repeating_interval('R3/1981-04-05/P1D', builder=AttoTimeBuilder))
[datetime.date(1981, 4, 5), datetime.date(1981, 4, 6), datetime.date(1981, 4, 7)]

Repeating intervals are allowed to go in the reverse direction:

>>> list(aniso8601.parse_repeating_interval('R2/PT1H2M/1980-03-05T01:01:00', builder=AttoTimeBuilder))
[attotime.attodatetime(1980, 3, 5, 1, 1, 0, 0, 0), attotime.attodatetime(1980, 3, 4, 23, 59, 0, 0, 0)]

Unbounded intervals are also allowed (Python 2):

>>> result = aniso8601.parse_repeating_interval('R/PT1H2M/1980-03-05T01:01:00', builder=AttoTimeBuilder)
>>> result.next()
attotime.attodatetime(1980, 3, 5, 1, 1, 0, 0, 0)
>>> result.next()
attotime.attodatetime(1980, 3, 4, 23, 59, 0, 0, 0)

or for Python 3:

>>> result = aniso8601.parse_repeating_interval('R/PT1H2M/1980-03-05T01:01:00', builder=AttoTimeBuilder)
>>> next(result)
attotime.attodatetime(1980, 3, 5, 1, 1, 0, 0, 0)
>>> next(result)
attotime.attodatetime(1980, 3, 4, 23, 59, 0, 0, 0)

The above treat years as 365 days and months as 30 days. Fractional months and years are supported accordingly:

>>> aniso8601.parse_interval('P1.1Y/2001-02-28', builder=AttoTimeBuilder)
(datetime.date(2001, 2, 28), datetime.date(2000, 1, 23))
>>> aniso8601.parse_interval('2001-02-28/P1Y2.5M', builder=AttoTimeBuilder)
(datetime.date(2001, 2, 28), datetime.date(2002, 5, 14))

Development

Setup

It is recommended to develop using a virtualenv.

Inside a virtualenv, development dependencies can be installed automatically:

$ pip install -e .[dev]

pre-commit is used for managing pre-commit hooks:

$ pre-commit install

To run the pre-commit hooks manually:

$ pre-commit run --all-files

Tests

Tests can be run using the unittest testing framework:

$ python -m unittest discover attotimebuilder

Contributing

attotimebuilder is an open source project hosted on Codeberg.

Any and all bugs are welcome on our issue tracker.

References

• aniso8601 and sub-microsecond precision