Package nltk :: Package sem :: Module evaluate :: Class Assignment

Class Assignment

object --+    
         |    
      dict --+
             |
            Assignment

A dictionary which represents an assignment of values to variables.

An assigment can only assign values from its domain.

If an unknown expression a is passed to a model M's interpretation function i, i will first check whether M's valuation assigns an interpretation to a as a constant, and if this fails, i will delegate the interpretation of a to g. g only assigns values to individual variables (i.e., members of the class IndividualVariableExpression in the logic module. If a variable is not assigned a value by g, it will raise an Undefined exception.

Instance Methods

[hide private]

new empty dictionary

__init__(self, domain, iter=None)
x.__init__(...) initializes x; see x.__class__.__doc__ for signature

source code

__getitem__(self, key)
x[y]

source code

a shallow copy of D

copy(self)

source code

purge(self, var=None)
Remove one or all keys (i.e.

source code

__str__(self)
Pretty printing for assignments.

source code

_addvariant(self)
Create a more pretty-printable version of the assignment.

source code

add(self, var, val)
Add a new variable-value pair to the assignment, and update self.variant. source code

Inherited from dict: __cmp__, __contains__, __delitem__, __eq__, __ge__, __getattribute__, __gt__, __hash__, __iter__, __le__, __len__, __lt__, __ne__, __new__, __repr__, __setitem__, clear, fromkeys, get, has_key, items, iteritems, iterkeys, itervalues, keys, pop, popitem, setdefault, update, values