[EMAIL PROTECTED] wrote: > I just started messing with programming and started with Python. Part > of my first project deals with translating numerical values to letters. > I would like to be able to do the reverse as well, letters to numbers, > sort of a table for lookup and a table for reverse lookup. I thought > that a dictionary would be the structure to use- write it once and in a > second instance swap the keys for values and values for keys. However, > reversing a dictionary does not seem to be easily achieved. Am I using > the wrong data structure? > This doesn't really answer your question (others have already done this), but back in the 'ol days we did this:
>>> letters=['a','b','c'] >>> map(lambda x: ord(x)-64, letters) [1, 2, 3] This takes advantage of the fact that letters must be stored as binary integers in ASCII (e.g. 'a' = 65, 'b'=66, etc.). You can go the other direction with chr(x). Not completely sure about what you want to accomplish, but this eliminates the need for the dictionaries. Larry Bates -- http://mail.python.org/mailman/listinfo/python-list
