_assertionnew.py 文件源码

def visit_Attribute(self, attr):
        if not isinstance(attr.ctx, ast.Load):
            return self.generic_visit(attr)
        source_explanation, source_result = self.visit(attr.value)
        explanation = "%s.%s" % (source_explanation, attr.attr)
        source = "__exprinfo_expr.%s" % (attr.attr,)
        co = self._compile(source)
        try:
            result = self.frame.eval(co, __exprinfo_expr=source_result)
        except Exception:
            raise Failure(explanation)
        explanation = "%s\n{%s = %s.%s\n}" % (self.frame.repr(result),
                                              self.frame.repr(result),
                                              source_explanation, attr.attr)
        # Check if the attr is from an instance.
        source = "%r in getattr(__exprinfo_expr, '__dict__', {})"
        source = source % (attr.attr,)
        co = self._compile(source)
        try:
            from_instance = self.frame.eval(co, __exprinfo_expr=source_result)
        except Exception:
            from_instance = True
        if from_instance:
            rep = self.frame.repr(result)
            pattern = "%s\n{%s = %s\n}"
            explanation = pattern % (rep, rep, explanation)
        return explanation, result