Creating a local variable scope.

Ethan Furman ethan at
Fri Sep 18 15:25:53 CEST 2009

Neal Becker wrote:
> markolopa at wrote:
>>On Sep 11, 7:36 pm, Johan Grönqvist <johan.gronqv... at> wrote:
>>>Hi All,
>>>I find several places in my code where I would like to have a variable
>>>scope that is smaller than the enclosing function/class/module
>>This is one of the single major frustrations I have with Python and a
>>important source of bugs for me. Here is a typical situation
>>for i, j in visited:
>>    a[i, j] = 1
>>for i in range(rows):
>>    a[i, 0] = 1
>>for j in range(columns):
>>    a[0, i] = 1
>>As you see the third loop has a bug (I am actually mixing two logics:
>>1) using i for rows and j for columns 2) using i for the first
>>iterator and j for the second). The result is a buggy code that is
>>tolerated by Python. In C++ or Perl I don't have this problem. I
>>wonder whether other people share this opinion and if we have ever had
>>PEPs trying to address that...
> I agree.  I wish there were a convenient way to switch this 'feature' 
> on/off.  I believe the vast majority of the time I do not want variable 
> names leaking out into other scopes.  OTOH, sometimes it's convenient.

loop != scope


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