Class StrictLookup

object --+    
         |    
LookupBase --+
             |
            StrictLookup

Strict variable lookup mechanism for expressions.

Referencing an undefined variable using this lookup style will immediately raise an UndefinedError:

>>> expr = Expression('nothing', lookup='strict')
>>> expr.evaluate({})
Traceback (most recent call last):
    ...
UndefinedError: "nothing" not defined

The same happens when a non-existing attribute or item is accessed on an existing object:

>>> expr = Expression('something.nil', lookup='strict')
>>> expr.evaluate({'something': dict()})
Traceback (most recent call last):
    ...
UndefinedError: {} has no member named "nil"