README
- Documentation:
- http://collections-extended.lenzm.net/
- GitHub:
- https://github.com/mlenzen/collections-extended
- PyPI:
- https://pypi.python.org/pypi/collections-extended
Overview
collections_extended
is a Python module providing
a bag
class, AKA multiset,
a setlist
class, which is a unique list or ordered set,
a bijection
class, RangeMap
which is a mapping from ranges to values and
a IndexedDict
class, which is an ordered mapping whose elements can be accessed using index,
in addition to key.
There are also frozen (hashable) varieties of bags and setlists.
Compatible with and tested against Python 3.6, 3.7, 3.8 & PyPy3.
Getting Started
>>> from collections_extended import bag, setlist, bijection, RangeMap, IndexedDict
>>> from datetime import date
>>> b = bag('abracadabra')
>>> b.count('a')
5
>>> b.remove('a')
>>> b.count('a')
4
>>> 'a' in b
True
>>> b.count('d')
1
>>> b.remove('d')
>>> b.count('d')
0
>>> 'd' in b
False
>>> sl = setlist('abracadabra')
>>> sl
setlist(('a', 'b', 'r', 'c', 'd'))
>>> sl[3]
'c'
>>> sl[-1]
'd'
>>> 'r' in sl # testing for inclusion is fast
True
>>> sl.index('d') # so is finding the index of an element
4
>>> sl.insert(1, 'd') # inserting an element already in raises a ValueError
Traceback (most recent call last):
...
raise ValueError
ValueError
>>> sl.index('d')
4
>>> bij = bijection({'a': 1, 'b': 2, 'c': 3})
>>> bij.inverse[2]
'b'
>>> bij['a'] = 2
>>> bij == bijection({'a': 2, 'c': 3})
True
>>> bij.inverse[1] = 'a'
>>> bij == bijection({'a': 1, 'c': 3})
True
>>> version = RangeMap()
>>> version[date(2017, 10, 20): date(2017, 10, 27)] = '0.10.1'
>>> version[date(2017, 10, 27): date(2018, 2, 14)] = '1.0.0'
>>> version[date(2018, 2, 14):] = '1.0.1'
>>> version[date(2017, 10, 24)]
'0.10.1'
>>> version[date(2018, 7, 1)]
'1.0.1'
>>> version[date(2018, 6, 30):] = '1.0.2'
>>> version[date(2018, 7, 1)]
'1.0.2'
>>> idict = IndexedDict()
>>> idict['a'] = "A"
>>> idict['b'] = "B"
>>> idict['c'] = "C"
>>> idict.get(key='a')
'A'
>>> idict.get(index=2)
'C'
>>> idict.index('b')
1
Installation
pip install collections-extended
Usage
from collections_extended import bag, frozenbag, setlist, frozensetlist, bijection
Classes
There are seven new classes provided:
Bags
- bag
- This is a bag AKA multiset.
- frozenbag
- This is a frozen (hashable) version of a bag.
Setlists
- setlist
- An ordered set or a list of unique elements depending on how you look at it.
- frozensetlist
- This is a frozen (hashable) version of a setlist.
Mappings
- bijection
- A one-to-one mapping.
- RangeMap
- A mapping from ranges (of numbers/dates/etc)
- IndexedDict
- A mapping that keeps insertion order and allows access by index.
Python 2
The package no longer supports Python 2. The last version to support Python 2.7, 3.4 & 3.5 was 1.0. No new feature releases will be done for 1.x but any significant bugs that come up may be fixed.
Author: | Michael Lenzen |
---|---|
Copyright: | 2020 Michael Lenzen |
License: | Apache License, Version 2.0 |
Project Homepage: | https://github.com/mlenzen/collections-extended |