示例#1
0
    def _rewrite_membership_op(self, node, left, right):
        # the kind of the operator (is actually an instance)
        op_instance = node.op
        op_type = type(op_instance)

        # must be two terms and the comparison operator must be ==/!=/in/not in
        if is_term(left) and is_term(right) and op_type in self.rewrite_map:

            left_list, right_list = map(_is_list, (left, right))
            left_str, right_str = map(_is_str, (left, right))

            # if there are any strings or lists in the expression
            if left_list or right_list or left_str or right_str:
                op_instance = self.rewrite_map[op_type]()

            # pop the string variable out of locals and replace it with a list
            # of one string, kind of a hack
            if right_str:
                self.env.remove_tmp(right.name)
                name = self.env.add_tmp([right.value])
                right = self.term_type(name, self.env)

            if left_str:
                self.env.remove_tmp(left.name)
                name = self.env.add_tmp([left.value])
                left = self.term_type(name, self.env)

        op = self.visit(op_instance)
        return op, op_instance, left, right
示例#2
0
    def prune(self, klass):

        def pr(left, right):
            """ create and return a new specialized BinOp from myself """

            if left is None:
                return right
            elif right is None:
                return left

            k = klass
            if isinstance(left, ConditionBinOp):
                if (isinstance(left, ConditionBinOp) and
                        isinstance(right, ConditionBinOp)):
                    k = JointConditionBinOp
                elif isinstance(left, k):
                    return left
                elif isinstance(right, k):
                    return right

            elif isinstance(left, FilterBinOp):
                if (isinstance(left, FilterBinOp) and
                        isinstance(right, FilterBinOp)):
                    k = JointFilterBinOp
                elif isinstance(left, k):
                    return left
                elif isinstance(right, k):
                    return right

            return k(self.op, left, right, queryables=self.queryables,
                     encoding=self.encoding).evaluate()

        left, right = self.lhs, self.rhs

        if is_term(left) and is_term(right):
            res = pr(left.value, right.value)
        elif not is_term(left) and is_term(right):
            res = pr(left.prune(klass), right.value)
        elif is_term(left) and not is_term(right):
            res = pr(left.value, right.prune(klass))
        elif not (is_term(left) or is_term(right)):
            res = pr(left.prune(klass), right.prune(klass))

        return res
示例#3
0
 def names(self):
     """Get the names in an expression"""
     if is_term(self.terms):
         return frozenset([self.terms.name])
     return frozenset(term.name for term in com.flatten(self.terms))
示例#4
0
文件: expr.py 项目: pannpers/pandas
 def names(self):
     """Get the names in an expression"""
     if is_term(self.terms):
         return frozenset([self.terms.name])
     return frozenset(term.name for term in com.flatten(self.terms))