changing a var by reference of a list

[Larry Bates]

Jorgen Bodde wrote:
> Hi,
> 
> I am trying to simplify my code, and want to automate the assigning of
> variables I get back from a set. I was thinking of putting the
> variables I want changed in a list:
> 
> L = [self._varA, self._varB ]
> 
> self._varA is a variable I want to change when I pass L to a function.
> I know doing this;
> 
> L[0] = 12
> 
> Will replace the entry self._varA with 12, but is there a way to
> indirectly change the value of self._varA, through the list, something
> like a by-reference in C++ or a pointer-pointer?
> 
> With regards,
> - Jorgen

You can make self._varA and self._varB instances of a class and
assign a value.  Not tested.

class _var:
    pass

self._varA=_var()
self._varB=_var()
L=[self._varA, self._varB]

then in function (or method of a class instance):

L[0].value=12

Another way is to use a class to pass everything:

class _vars:
    def __init__(self, vars=None):
        if vars is not None:
            for varname, value in vars.items():
                setattr(self, varname, value)
        return


vars=_vars({'_varA': 0, '_varB': 0})

Then you can access:

vars._varA
vars._varB

-Larry

l