Pure Python OrderedSet implementation built on top of collections.OrderedDict

OrderedSet is a collection of hashable objects, which also remembers the injection order. This implementation is a bit dirty and quick hack to create a pure python object based on collections.OrderedDict. It is very light, and has absolutely no dependencies. All functions and operators defined on the built-in set object are also available on OrderedSet.

None.

On Linux and Macintosh:

$ git clone https://github.com/petervaro/orderedset.git
$ cd orderedset
$ sudo python3 setup.py install

Create an OrderedSet of various items and print it:

from orderedset import OrderedSet

s = OrderedSet(['hello', True, None, 1, 3.14])
print(s)
for i, item in enumerate(s):
    print(i, '=>', item)

And the output is:

OrderedSet(['hello', True, None, 3.14])
0 => hello
1 => True
2 => None
3 => 3.14

NOTE: One very important difference is, that an OrderedSet can only be compared to another OrderedSet via the == and != operators. Also two OrderedSets are equal if and only if both have the exact same items and their orders are the same as well.