omdict is an ordered multivalue dictionary that retains method parity with Python's dict and helps power furl.

A multivalue dictionary is a dictionary that can store multiple values per key. An ordered multivalue dictionary is a multivalue dictionary that retains the order of insertions and deletions.

orderedmultidict is well tested, Unlicensed in the public domain, supports Python 2, Python 3, PyPy2, and PyPy3.

Code time: omdict can store multiple values per key.

>>> from orderedmultidict import omdict
>>> omd = omdict()
>>> omd[1] = 1
>>> omd[1]
1
>>> omd.add(1, 11)
>>> omd.getlist(1)
[1, 11]
>>> omd.addlist(1, [111, 1111])
>>> omd.getlist(1)
[1, 11, 111, 1111]
>>> omd.allitems()
[(1, 1), (1, 11), (1, 111), (1, 1111)]

omdict retains insertion and deletion order.

>>> omd = omdict()
>>> omd[2] = 2
>>> omd[1] = 1
>>> omd.items()
[(2, 2), (1, 1)]
>>> omd[2] = 'sup'
>>> omd.items()
[(2, 'sup'), (1, 1)]

Method parity with dict is retained; omdict can be a drop-in replacement.

>>> d, omd = dict(), omdict()
>>> d.update([(1,1), (1,11), (2,2), (2,22)])
>>> omd.update([(1,1), (1,11), (2,2), (2,22)])
>>> d[1], omd[1]
(11, 11)
>>> d[3] = 3
>>> omd[3] = 3
>>> d.get(3), omd.get(3)
(3, 3)
>>> d.items() == omd.items()
True

API

See all of omdict's methods, with examples, in omdict's API document, API.md.

Installation

Installing orderedmultidict with pip is easy.

$ pip install orderedmultidict