python-edtf

A partial implementation of EDTF format in Python.

See <http://www.loc.gov/standards/datetime/> for the draft specification.

To install

pip install edtf

Includes:

Level 0 ISO 8601 Features

• Date
• Interval (start/end)

Level 1 Extensions

• Uncertain/Approximate dates
• Unspecified dates
• Year exceeding four digits
• Season

Level 2 Extensions

• Partial unspecified
• Masked precision

Also

• A rough and ready plain text parser
• Basic conversion to python dates for sorting and range testing

Does not include (ie still to be implemented):

Level 0 ISO 8601 Features

• Times
• Interval (start/end)

Level 1 Extensions

• L1 Extended Interval

Level 2 Extensions

• partial uncertain/approximate
• one of a set
• multiple dates
• L2 extended Interval
• Year requiring more than 4 digits - Exponential form

Usage

>>> from edtf import EDTF
>>> e = EDTF('1898-uu~')  # approximately a month in 1898
>>> e.date_earliest()  # approximate dates get a bit of padding
datetime.date(1897, 12, 16)
>>> e.date_latest()
datetime.date(1899, 1, 16)
>>> e.sort_date_earliest() # defaults to be at the start of the range
datetime.date(1898, 01, 01)
>>> e.sort_date_latest() # defaults to be at the end of the range
datetime.date(1898, 12, 31)
>>> e.is_interval
False

>>> i = EDTF('1898/1903-08-30')  # between 1898 and August 30th 1903
>>> i.earliest_date()
datetime.date(1898, 1, 1)
>>> i.date_latest()
datetime.date(1903, 8, 30)
>>> i.sort_date_earliest()
datetime.date(1898, 01, 01)
>>> i.sort_date_latest()
datetime.date(1903, 08, 30)
>>> i.is_interval
True

>>> p = EDTF.from_natural_text("circa April 1912")
>>> unicode(p)
u'1912-04~'
>>> p.sort_date_earliest()
datetime.date(1912, 4, 01)
>>> p.sort_date_latest()
datetime.date(1912, 4, 30)