On Wed, 22 Jun 2016 07:24 pm, BartC wrote: [...] > But even if it worked, I don't think this two-parter counts as a 'global > variable' as it is understood. I might as well just create my own G > module containing: > > BDFL="GvR" > > and import it in both A and B. Then I can also write G.BDFL in those > modules. But remember the point was avoid having to write Test.test_var.
The question "Does Python have global variables?" depends on what you mean by "global variable". That makes it a dispute about definitions, and we know how they go: http://lesswrong.com/lw/np/disputing_definitions/ So what do *I* mean by global variables? To me, a global variable is a variable which is scoped to a level wider than any single function, i.e. module scope, or whole-application scope. That is, the variable must be visible to more than one function, or more than one module. But further, you must be able to *assign* to that variable with a simple assignment, without explicitly prefixing the variable with a namespace: foo = 1 It is okay if you have to declare that the variable is global before assigning to it. So to me, Python has module globals, because you can have two functions in the one module which both assign to the same variable: def spam(): global x x = 1 def ham(): global x x = 2 x is a global variable. But Python *doesn't* have application-wide globals, because although you can access a variable across multiple modules at the same time, you cannot do so without using the fully-qualified name module.x rather than just x. (To be precise, for the builtins module specifically, you can *read* the value of the variable using just x, but you cannot *assign* to it unless you use the fully-qualified name builtins.x.) If Rick wishes to argue for a different definition of "global variable", Rick should explain what his definition is, and why we should prefer it to mine. -- Steven -- https://mail.python.org/mailman/listinfo/python-list
