[Python-Dev] more timely detection of unbound locals

[Nick Coghlan]

On Tue, May 10, 2011 at 11:11 PM, R. David Murray <rdmurray at bitdance.com> wrote:
> How about:
>
> "reference to variable 'y' precedes an assignment that makes it a local
> variable"

For comparison, the error messages I was able to elicit from 2.7 were
as follows:

# Module level
NameError: name 'bob' is not defined

# Function level reference to implicit global
NameError: global name 'bob' is not defined

# Early reference to local
UnboundLocalError: local variable 'bob' referenced before assignment

# Early reference from closure
NameError: free variable 'bob' referenced before assignment in enclosing scope

Personally, I would just add "in current scope" to the existing error
message for the unbound local case (and potentially collapse the
exception hierarchy a bit by setting UnboundLocalError = NameError).

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia