python - 如何在 python 代码中利用 locals()？

Question

我在阅读 Code Like a Pythonista: Idiomatic Python 时偶然发现了以下警告大卫·古杰 (David Goodger)。

Excerpt from the article ...

print('Hello %(name)s, you have %(messages)i messages' % locals())

This is very powerful. With this, you can do all the string formatting you want without having to worry about matching the interpolation values to the template.

But power can be dangerous. "With great power comes great responsibility." If you use the locals() from with an externally-supplied template string, you expose your entire local namespace to the caller. This is just something to keep in mind.

我正在尝试了解使用 locals() 可能很危险的特定场景。任何有关如何利用代码中存在的 locals() 的示例都值得赞赏。谢谢!

Answer 1

示例，简单的代码:

script_name = 'readpw.py'
...
entered_pw = raw_input()
if entered_pw != real_pw:
    print "%(script_name)s: The password you entered: "+entered_pw+" is incorrect."%locals()

考虑 entered_pw 为 %(real_pw)s

的情况