How do I do this? (eval() on the left hand side)
itsme at yahoo.com
Tue Dec 7 22:41:34 CET 2004
Yes, Russell, what you suggested works.
I have to chew more on the syntax to see how this is working.
because in the book that I have, it says:
exec code [ in globaldict [, localdict] ]
"Russell Blau" <russblau at hotmail.com> wrote in message
news:31ml9mF3d9csnU1 at individual.net...
> "It's me" <itsme at yahoo.com> wrote in message
> news:Y0ptd.39767$6q2.23845 at newssvr14.news.prodigy.com...
> > In REXX, for instance, one can do a:
> > interpret y' = 4'
> > Since y contains a, then the above statement amongs to:
> > a = 4
> > There are many situations where this is useful. For instance, you
> > getting an input which is a string representing the name of a variable
> > you wish to evaluate the expression (like a calculator application, for
> > instance).
> In Python, the canonical advice for this situation is, "Use a dictionary."
> This has a number of advantages, including keeping your user's namespace
> separate from your application's namespace. Plus it's easier to debug and
> maintain the code.
> But, if you absolutely, positively have to refer to your variable
> indirectly, you could do:
> exec "%s = 4" % y
> If y refers to the string "a", this will cause the variable a to refer to
> the value 4.
> I don't actually read my hotmail account, but you can replace hotmail with
> excite if you really want to reach me.
More information about the Python-list