rewrite.py 文件源码

def visit_Compare(self, comp):
        self.push_format_context()
        left_res, left_expl = self.visit(comp.left)
        if isinstance(comp.left, (_ast.Compare, _ast.BoolOp)):
            left_expl = "({0})".format(left_expl)
        res_variables = [self.variable() for i in range(len(comp.ops))]
        load_names = [ast.Name(v, ast.Load()) for v in res_variables]
        store_names = [ast.Name(v, ast.Store()) for v in res_variables]
        it = zip(range(len(comp.ops)), comp.ops, comp.comparators)
        expls = []
        syms = []
        results = [left_res]
        for i, op, next_operand in it:
            next_res, next_expl = self.visit(next_operand)
            if isinstance(next_operand, (_ast.Compare, _ast.BoolOp)):
                next_expl = "({0})".format(next_expl)
            results.append(next_res)
            sym = binop_map[op.__class__]
            syms.append(ast.Str(sym))
            expl = "%s %s %s" % (left_expl, sym, next_expl)
            expls.append(ast.Str(expl))
            res_expr = ast.Compare(left_res, [op], [next_res])
            self.statements.append(ast.Assign([store_names[i]], res_expr))
            left_res, left_expl = next_res, next_expl
        # Use pytest.assertion.util._reprcompare if that's available.
        expl_call = self.helper("call_reprcompare",
                                ast.Tuple(syms, ast.Load()),
                                ast.Tuple(load_names, ast.Load()),
                                ast.Tuple(expls, ast.Load()),
                                ast.Tuple(results, ast.Load()))
        if len(comp.ops) > 1:
            res = ast.BoolOp(ast.And(), load_names)
        else:
            res = load_names[0]
        return res, self.explanation_param(self.pop_format_context(expl_call))