[Python-3000] Proposed changes to PEP3101 advanced string formatting -- please discuss and vote!

[Eric V. Smith]

Eric V. Smith wrote:
> Nick Coghlan wrote:
>>> Feature:  Exception raised if attribute with leading underscore accessed.
>>>
>>> The syntax supported by the PEP is deliberately limited in an attempt
>>> to increase security.  This is an additional security measure, which
>>> is on by default, but can be optionally disabled if
>>> string.flag_format() is used instead of 'somestring'.format().
>> -0
>>
>> This is only an issue if implicit access to locals()/globals() is 
>> permitted, and is unlikely to help much in that case (underscores are 
>> rarely used with local variables, and those are the most likely to 
>> contain juicy information which may be leaked)
> 
> That's not true.  What this feature is trying to prevent is access to 
> attributes of the passed in objects.  For example:

I should have said "It's not an issue only if locals()/globals() are 
allowed".  It is true that automatic locals()/globals() magnifies this 
issue, but it exists even without it.

Eric.