问题描述
我实在想不出 Python 需要 del 关键字的任何原因(而且大多数语言似乎没有类似的关键字).例如，与其删除一个变量，不如将 None 赋值给它.当从字典中删除时，可以添加一个del方法.
I can't really think of any reason why Python needs the del keyword (and most languages seem to not have a similar keyword). For instance, rather than deleting a variable, one could just assign None to it. And when deleting from a dictionary, a del method could be added.
是否有理由在 Python 中保留 del，还是 Python 前垃圾收集时代的遗迹?
Is there a reason to keep del in Python, or is it a vestige of Python's pre-garbage collection days?
推荐答案
首先，除了局部变量，你还可以删除其他东西
Firstly, you can del other things besides local variables
del list_item[4]
del dictionary["alpha"]
这两者都应该是非常有用的.其次，在局部变量上使用 del 使意图更清晰.比较:
Both of which should be clearly useful. Secondly, using del on a local variable makes the intent clearer. Compare:
del foo
到
foo = None
我知道在 del foo 的情况下，目的是从作用域中删除变量.目前尚不清楚 foo = None 是否正在这样做.如果有人只是分配了 foo = None，我可能会认为这是死代码.但我立刻知道编写del foo 代码的人想做什么.
I know in the case of del foo that the intent is to remove the variable from scope. It's not clear that foo = None is doing that. If somebody just assigned foo = None I might think it was dead code. But I instantly know what somebody who codes del foo was trying to do.
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