Tim Chase wrote: > vsoler wrote: >> Hence, I need to parse Excel formulas. Can I do it by means only of re >> (regular expressions)? >> >> I know that for simple formulas such as "=3*A7+5" it is indeed >> possible. What about complex for formulas that include functions, >> sheet names and possibly other *.xls files? > > Where things start getting ugly is when you have nested function calls, > such as > > =if(Sum(A1:A25)>42,Min(B1:B25), if(Sum(C1:C25)>3.14, > (Min(C1:C25)+3)*18,Max(B1:B25))) > > Regular expressions don't do well with nested parens (especially > arbitrarily-nesting-depth such as are possible), so I'd suggest going > for a full-blown parsing solution like pyparsing. > > If you have fair control over what can be contained in the formulas and > you know they won't contain nested parens/functions, you might be able > to formulate some sort of "kinda, sorta, maybe parses some forms of > formulas" regexp. > And don't forget about named ranges, which can reference cells without using anything but a plain identifier ...
regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 PyCon is coming! Atlanta, Feb 2010 http://us.pycon.org/ Holden Web LLC http://www.holdenweb.com/ UPCOMING EVENTS: http://holdenweb.eventbrite.com/ -- http://mail.python.org/mailman/listinfo/python-list
