I half-answer to myself :
> 1. be able to convert a string into a function on which I can use Sage s = "x**3" var('x') f = eval(s) print f(3) makes the job > 2. from the results of Sage (especially from diff(f,x)), I need a > string that I can manipulate with Python (especially use the .replace > method in order to produce strings that are valid code for pstricks). s = "x**3" var('x') f = eval(s) print f(3) g = diff(f,x) print g I would like to get the string "3*(x**2)" or something like that. Thanks for any ideas Laurent --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---