[ python-Bugs-215126 ] Over restricted type checking on eval() function

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Bugs item #215126, was opened at 2000-09-22 14:36
Message generated for change (Settings changed) made by rhettinger
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https://sourceforge.net/tracker/?func=detail&atid=105470&aid=215126&group_id=5470

Category: Python Interpreter Core
Group: Feature Request
>Status: Open
Resolution: Later
Priority: 5
Submitted By: Nobody/Anonymous (nobody)
>Assigned to: Raymond Hettinger (rhettinger)
Summary: Over restricted type checking on eval() function

Initial Comment:
The built-in function eval() takes a string argument and a dictionary.  The second argument should allow any instance which defines __getitem__ as opposed to just dictionaries.

The following example creates a type error:
  eval, argument 2: expected dictionary,   instance found

class SpreadSheet:
    _cells = {}
    def __setitem__( self, key, formula ):
        self._cells[key] = formula
    def __getitem__( self, key ):
        return eval( self._cells[key], self )

ss = SpreadSheet()
ss['a1'] = '5'
ss['a2'] = 'a1*5'
ss['a2']


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Comment By: Tim Peters (tim_one)
Date: 2000-09-22 23:18

Message:
Added to PEP 42.

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Comment By: Tim Peters (tim_one)
Date: 2000-09-22 14:42

Message:
Changed Group to Feature Request.  Should be added to PEP 42 (I'll do that if nobody beats me to it).

CPython requires a genuine dict now for speed.  I believe JPython allows any mapping object.


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https://sourceforge.net/tracker/?func=detail&atid=105470&aid=215126&group_id=5470