MIDict (Multi-Index Dict)

MIDict is an ordered "dictionary" with multiple indices where any index can serve as "keys" or "values", capable of assessing multiple values via its powerful indexing syntax, and suitable as a bidirectional/inverse dict (a drop-in replacement for dict/OrderedDict in Python 2 & 3).

Features

• Multiple indices
• Multi-value indexing syntax
• Convenient indexing shortcuts
• Bidirectional/inverse dict
• Compatible with normal dict in Python 2 & 3
• Accessing keys via attributes
• Extended methods for multi-indices
• Additional APIs to handle indices
• Duplicate keys/values handling

Quickstart

name	uid	ip
jack	1	192.1
tony	2	192.2

The above table-like data set (with multiple columns/indices) can be represented using a MIDict:

user = MIDict([['jack', 1, '192.1'], # list of items (rows of data)
               ['tony', 2, '192.2']],
              ['name', 'uid', 'ip']) # a list of index names

Access a key and get a value or a list of values (similar to a normal dict):

user['jack'] == [1, '192.1']

Any index (column) can be used as the "keys" or "values" via the advanced "multi-indexing" syntax d[index_key:key, index_value]. Both index_key and index_value can be a normal index name or an int (the order the index), and index_value can also be a tuple, list or slice object to specify multiple values, e.g.:

user['name':'jack', 'uid'] == 1
user['ip':'192.1', 'name'] == 'jack'

user['name':'jack', ('uid', 'ip')] == [1, '192.1']
user[0:'jack', [1, 2]]             == [1, '192.1']
user['name':'jack', 'uid':]        == [1, '192.1']

The "multi-indexing" syntax also has convenient shortcuts:

user['jack'] == [1, '192.1']
user[:'192.1'] == ['jack', 1]
user['jack', :] == ['jack', 1, '192.1']

A MIDict with 2 indices can be used as a bidirectional/inverse dict:

color = MIDict(red='#FF0000', green='#00FF00')

color['red']      == '#FF0000' # forward indexing: d[key] -> value
color[:'#FF0000'] == 'red'     # backward/inverse indexing: d[:value] -> key

Documentation

See https://midict.readthedocs.io

Installation

pip install midict

PyPI repository: https://pypi.python.org/pypi/midict

Development

Source code: https://github.com/ShenggaoZhu/midict

Report issues: https://github.com/ShenggaoZhu/midict/issues/new

Testing

python tests/tests.py

Tested with both Python 2.7 and Python 3,3, 3.4, 3.5.