Hello As part of the MathTran project I found myself wanting to maintain a bijection between long names and short names. http://www.open.ac.uk/mathtran
In other words, I wanted to have two dictionaries f and g such that f[a] == b g[b] == a are equivalent statements. A google search for biject.py and bijection.py produced no hits, so I suspect that this may not have been done before. I've written a partial implementation of this, and would appreciate comments. http://texd.cvs.sourceforge.net/texd/tex/util.py?revision=1.1&view=markup http://texd.cvs.sourceforge.net/texd/test_tex/test_util.py?revision=1.1&view=markup Here's the code from test_util.py, that shows how it works. The weakref stuff is so that there isn't a circular reference f to g to f. === from tex.util import biject f, g = biject() assert f.inverse is g assert g.inverse is f f[1] = 2 assert f[1] == 2 assert g[2] == 1 assert f.has_value(2) import weakref wr_g = weakref.ref(g) del g assert wr_g() == None assert f.inverse == None === best regards Jonathan -- http://mail.python.org/mailman/listinfo/python-list