A sorted mapping object.

sortedmap is a python dict api interface to the C++ std::map type. sortedmap implements the full dict object interface with a few differences:

1. Objects are stored in a red black tree. All keys must be comparable to eachother though they do not need to be hashable. This means all keys must implement at least __lt__ and __eq__.
2. O(log(n)) lookup, insert, and deletes because of the red- black tree backing. This is worse than dict which offers O(1) lookup, insert, and delete. The C++ implementation offers low constants
3. Iteration is in sorted order for .keys() , .values() and .items().
4. popitem accepts a first=True argument which says to pop from the front or the back. dict.popitem pops an abitrary item; however sortedmap pops the first or the last item.
5. Method names and semantics from Python 3 are picked over Python 2. This means that .keys() returns a keyview instead of a list and there is no .keyview() method. This shares more code across Python 2 and 3 and anything that is possible with the Python 2 interface is possible with the Python 3 interface.

6. Optional keyfunc for defining the sort order. By default this is the identity function. A different key function can be set at object construction time like:

   sortedmap[keyfunc](...)

   This can be retrieved later with the keyfunc attribute of sortedmap objects.

sortedmap has no python package depencencies but requires CPython 2.7 or >=3.4. sortedmap depends on CPython 2 or 3 and some means of compiling C++14. We recommend using g++ to compile sortedmap. Compilation and testing was done with gcc 5.3.0

sortedmap is free software, licensed under the GNU Lesser General Public License, version 2.1. For more information see the LICENSE file.

Source code is hosted on github at https://github.com/llllllllll/sortedmap.