[GRASS-dev] python question

[Glynn Clements]

Michael Barton wrote:

> This is probably simple but I'm missing something somewhere. How can
> I dynamically create variable names and then assign values to the
> variables? I need to do something along the lines of:
> 
> for i in flist:
> 	's%_new' % i = 10
> 
> where flist is a list of strings (e.g., file names)

You can create new global (module-scope) variables by adding them to
the dictionary returned by the globals() function.

You cannot dynamically create local variables, as the parser has to
find the variable in the function body at parse time in order for it
to be treated as a local variable. You can retrieve a dictionary of
local variables using the locals() function, but the result should not
be modified.

You can dynamically get/set object members using getattr() and
setattr().

But you should really try to avoid accessing variables dynamically, as
it makes the code harder to follow (e.g. grepping for occurrences of
"something_new" won't find the above). Wherever possible, use
dictionaries instead.

-- 
Glynn Clements <glynn at gclements.plus.com>