Feature Request: delete variable from memory when it has been removed/renamed

[aamster]

The problem is that when there is a variable, say foo, but then foo has been renamed for example, and there is some other code that references foo within the notebook, then this other code might be using a variable which you intended to remove or rename. To me, it's a common annoyance with notebook coding, and I'm sure to others as well.

Of course if you are using an IDE and a variable has been removed from the script, then the IDE should prompt you that it doesn't exist if it is being used. In the notebook it's more difficult because all variables are stored in the same memory once they are created.

To handle it, just as a thought, if a cell contained a variable named foo, then when that cell is re-executed and foo is no longer declared, then remove foo from memory and provide UI feedback that is has been removed from memory. I'm sure there's other edge cases.

[StKyr]

I agree. Allowing variables that do not appear into the code to exist in memory can lead to an array of bugs since it is extremely likely for programmers to forget renaming some of instance of the old variable and Python will not raise a NameError which sounds very dangerous to me.

Perhaps this functionality could be added as an option