[Tutor] Addressing a variable whose name is the value of a string

[Kent Johnson]

Andreas Pfrengle wrote:
> # Accessing db (see http://www.djangoproject.com/documentation/db-api/):
> myobj = MyModel.objects.get(<some filter>)
> var = myobj.vector
> # vector is a Textfield, so var now contains a string, naming another 
> db-field of myobj
> 
> execstr = "attr = myobj." + var
> exec execstr
> # attr now contains the content of the field named in var (an int in my 
> case)

Use
attr = getattr(myobj, var)

> attr += 42    #some calculation with attr
> 
> execstr = "myobj." + var + " = attr"
> exec execstr

setattr(myobj, var, attr)

Kent