Package: dateformat
`dateformat` does two things:  turn `datetime` objects into strings, and turn strings into `datetime` objects.It's goal is to do these things simply and well, and to satisfy the following criteria:* Be fast enough (see below for benchmarks)* Handle a variety of date formats from multiple sources* Parse and format dates in many timezones and with many timezone offsets* Represent the expected format in a way that a non-technical person may understand* Be explicit about the expected format to prevent heuristic errors> "But why another date library?"There isn't currently a python library I've been able to find that matches theserequirements well enough for my use-cases.  [`Arrow`](http://arrow.readthedocs.io/en/latest/)comes closest, but still isn't quite suitable performance-wise.# UsageAll functionality is based around DateFormat() objects:### `def __init__(self, spec, is_24hour=None)`create a dateformat object from the provided spec string.```>>> from dateformat import DateFormat>>> date_format = DateFormat("YYYY-MM-DD hh:mm:ss.SSSS+HH:MM")```If `is_24hour` is not provided, the format will be in 12-hour mode if an am/pmpart is present in the spec, otherwise, dates will be in 24-hour mode.DateFormat instances have two methods:### `def parse(self, data)`Parse a string(`data`) containing a date into a datetime object.```>>> date = date_format.parse("2017-06-03 15:32:00.2364-02:00")datetime.datetime(2017, 6, 3, 15, 32, 0, 236400, tzinfo=datetime.timezone(datetime.timedelta(-1, 79200)))```### `def format(self, date)`Format the passed in `datetime.datetime` object (`date`) as a string:```>>> print(date_format.format(date))2017-06-03 15:32:00.2364-02:00```## TimezonesIf any part of the format provides a timezone, or UTC offset, then parsingproduces dates with a timezone indicating the relevant UTC offset.Likewise, if a dateformat has a timezone part, then dates passed to `.format()`must include a tzinfo value.If pytz is available, then some level of named timezone support is provided.## Leading zerosAll numeric parts of the date format are zero-padded to the number of charactersin the spec.  I.e.  'DD' means that the day of the month is zero-padded to 2-digits.During parsing, a missing leading zero is usually ignored, but if there is no separatorbetween parts (for example:  YYYYMMDD), then a missing leading zero will cause an error or bad value.Currently, all formatted dates are zero-padded, in the future, this may be controllable.## Date format specification| Part | Example | Description ||---------|---------|---------------|| `+HHMM` | -0515 | A UTC offset provided as a 2-digit hour, and 2-digit minute, with no separator || `+HH:MM` | -05:15 | A UTC offset provided as a 2-digit hour, and 2-digit minute, with a ':' separator || `+HH` | -05 | A UTC offset provided as a 2-digit hour only || `Dddddd` | Monday | The full locale-specific day of the week (Note, this value is ignored during date parsing, but added during date format) || `Ddd` | Mon | The locale-specific short name for the day of the week (Ignored during parsing) || `DD` | 05 | The zero-padded day of the month. || `MMMMM` | September | Month as locale’s full name || `MMM` | Sep | Month as locale’s abbreviated name || `YYYY` | 2017 | Year with century as a number || `YY` | 17 | Year without century as a zero-padded number || `hh` | 09 | Hour as a zero-padded number || `mm` | 06 | Minute as a zero-padded number || `ss` | 45 | Second as a zero-padded number || `SSSSSS` | 123456 | Microsecond as a zero-padded decimal number || `SSSS`   | 1234 | 100-microseconds as a zero-padded number || `SSS` | 123 | milliseconds as a zero-padded number || `SS` | 12 | 10-milliseconds as a zero-padded number || `am` `Am` `AM` `pm` `Pm` `PM` | am | either AM or PM depending on the hour.  `.format()` matches the case of the spec.  If present, the dateformat will default to 12-hour mode || `of` | | Ignored during parsing, added during formtting || `st` | th | The appropriate suffix for the day of the month, for example '1_st_ July', '2_nd_ March' || `␣` | T | (Unicode OPEN BOX - U+2423) Matches either the character 'T' or a space ' '.  During formatting, 'T' is always used (this is provided to improve flexibility when parsing iso8601 formats) || space | | Matches one or more spaces during parsing.  During formatting, one space will be output || any of `:/-.,TZ()` | | Ignored during parsing, output as-is during formatting |# Examples| Format                   | Example                ||--------------------------|------------------------|| `YYYY-MM-DDThh:mm:ss`    | 2017-06-06T09:45:15    || `YYYYMMDDhhmmss`         | 20170606094515         || `YYYYMMDDhhmmss.SSSSSSZ` | 20170606094515.123456Z || `MM/DD/YY hh:mm+HHMM`    | 06/06/17 09:45-0500    |# Library comparison## dateformat ⇄ datetime (builtin python module)Dateformat is *not* trying to be a replacement for the builtin datetime module.  `datetime.datetime` objects are used as the input/output to the parsing and formatting methods.It is designed as a replacement for the  `datetime.datetime.strftime` and `datetime.datetime.strptime` methods, providing:* better timezone handling* a simpler/more common syntax for specifying the date formats* slightly faster parsing## dateformat ⇄ dateutil.parser.parse()`dateutil.parser.parse`'s intent is to turn a string in an unknown format into a date.  It does that by using a variety of heuristics to try to figure out the format the date has been expressed in.This approach is highly useful, and very flexible, but suffers from a couple of drawbacks that dateformat doesn't have:* There is ambiguity about what date will be produced from a given string, there are situations where that risk cannot be accepted, and it's important for the system to only accept a certain date format* Because of all the work that dateutil is doing to work out the format used, it's fairly slow, at just under 10x slower than `strptime`, this is very noticable over 10s - 100s thousands of dates.## dateformat ⇄ arrowarrow is the closest to the way dateformat works, the syntax for describing dates is very similar. Unfortunately, arrow constructs its parser every time a date is parsed, creating a significant overhead when parsing each date.## dateformat ⇄ iso8601 / ciso8601ciso8601 is _really_ fast.  Unfortunately both these libraries only handle a single date format, so are not useful in this situation.# Benchmarksthe `benchmark/` dir contains some simple scripts to show how the relative libraries perform at parsing and formatting dates.Running on a 2016 macbook pro, on Python 3.6.3 gave the following results (best of 3 runs):(Please note, the parse time chart y-axis has been clamped to 1s, but dateparser took 16s to complete)![chart showing relative date parse performance](https://github.com/stestagg/dateformat/raw/master/benchmark/parse_times.png)![chart showing relative date format performance](https://github.com/stestagg/dateformat/raw/master/benchmark/format_times.png)Keywords: date time parsing formatting datetimePlatform: UNKNOWNClassifier: Development Status :: 3 - AlphaClassifier: Intended Audience :: DevelopersClassifier: Topic :: Software Development :: Build ToolsClassifier: License :: OSI Approved :: MIT LicenseClassifier: Programming Language :: Python :: 3Classifier: Programming Language :: Python :: 3.3Classifier: Programming Language :: Python :: 3.4Classifier: Programming Language :: Python :: 3.5Provides-Extra: test