Evaluates an expression on scored documents.
def google.appengine.api.search.stub.expression_evaluator.ExpressionEvaluator.__init__ |
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self, |
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document, |
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inverted_index, |
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is_sort_expression = False |
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) |
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Constructor.
Args:
document: The ScoredDocument to evaluate the expression for.
inverted_index: The search index (used for snippeting).
is_sort_expression: The flag indicates if this is a sort expression. Some
operations (such as COUNT) are not supported in sort expressions.
def google.appengine.api.search.stub.expression_evaluator.ExpressionEvaluator.Evaluate |
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self, |
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expression |
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Evaluates the expression for a document and attaches the result.
Args:
expression: The Expression protobuffer object.
def google.appengine.api.search.stub.expression_evaluator.ExpressionEvaluator.ValueOf |
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self, |
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expression, |
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default_value = None , |
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return_type = None |
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) |
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Returns the value of an expression on a document.
Args:
expression: The expression string.
default_value: The value to return if the expression cannot be evaluated.
return_type: The type the expression should evaluate to. Used to create
multiple sorts for ambiguous expressions. If None, the expression
evaluates to the inferred type or first type of a field it encounters in
a document.
Returns:
The value of the expression on the evaluator's document, or default_value
if the expression cannot be evaluated on the document.
Raises:
ExpressionEvaluationError: sort expression cannot be evaluated
because the expression or default value is malformed. Callers of
ValueOf should catch and return error to user in response.
QueryExpressionEvaluationError: same as ExpressionEvaluationError but
these errors should return query as error status to users.
The documentation for this class was generated from the following file:
- code/googleappengine-read-only/python/google/appengine/api/search/stub/expression_evaluator.py