[Zope] Verrryy strange behavior (NameError)

[Dieter Maurer]

Andrew Athan writes:
 > This is a multi-part message in MIME format.
 > 
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Please avoid MIME messages!

 > ...
 > _stateVariable=0
 > .....
 > class ....
 > def fun()
 >    ....
 >    _stateVariable=1
 > 
 > 
 > and this was causing me all kinds of grief.  By changing the code to
 > 
 > _stateVariable = {'a':0}
 > ....
 > class ...
 > def fun()
 >    ...
 >    _stateVariable['a']=1
 > 
 > everything works just fine.  Now, can someone give me the shortcut to
 > understand WHHHYYY?
When Python sees an assignment to a *variable*, it assumes
you want to define a new *local* variable.
You must explicitly declare it "global" to be able to change
the value of a global variable from a local context.

In the second case, you do not assign to a variable, but
modify an object (leaving all variable binding unchanged).


Dieter