def evaluate(self, field=0):
        """ Return the value of the first field from the next record
        (or the value of another field if explicitly specified).

        This method attempts to move the cursor one step forward and,
        if successful, selects and returns an individual value from
        the new current record. By default, this value will be taken
        from the first value in that record but this can be overridden
        with the `field` argument, which can represent either a
        positional index or a textual key.

        If the cursor cannot be moved forward or if the record contains
        no values, :py:const:`None` will be returned instead.

        This method is particularly useful when it is known that a
        Cypher query returns only a single value.

        :param field: field to select value from (optional)
        :returns: value of the field or :py:const:`None`

        Example:
            >>> from py2neo import Graph
            >>> g = Graph()
            >>> g.run("MATCH (a) WHERE a.email={x} RETURN a.name", x="bob@acme.com").evaluate()
            'Bob Robertson'
        """
        if self.forward():
            try:
                return self._current[field]
            except __HOLE__:
                return None
        else:
            return None
dataset/ETHPy150Open nigelsmall/py2neo/py2neo/database/__init__.py/Cursor.evaluate