Documentation: http://collections-extended.lenzm.net/
GitHub: https://github.com/mlenzen/collections-extended
PyPI: https://pypi.python.org/pypi/collections-extended
collections_extended, provides
a bag class, AKA multiset,
a setlist class, which is a unique list or ordered set,
and a bijection class.
There are also frozen (hashable) varieties of bags and setlists.
Tested against Python 2.6, 2.7, 3.2, 3.3, 3.4 & PyPy.
>>> from collections_extended import bag, setlist, bijection
>>> 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})
Truepip install collections-extended
from collections_extended import bag, frozenbag, setlist, frozensetlist, bijection
There are five new classes provided:
- bag
- This is a bag AKA multiset.
- frozenbag
- This is a frozen (hashable) version of a bag.
- 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.
- bijection
- A one-to-one mapping.
A Collection factory is provided where you can specify whether you want the Collection returned to be mutable, have unique elements and/or be ordered. If an Iterable object is passed the Collection will be filled from it, otherwise it will be empty.
collection(it = None, mutable=True, unique=False, ordered=False)
| Author: | Michael Lenzen |
|---|---|
| Copyright: | 2015 Michael Lenzen |
| License: | Apache License, Version 2.0 |
| Project Homepage: | https://github.com/mlenzen/collections-extended |