Auto destruct variables after loop scope-end

Question

Unlike other languages like c, c++ where the scope of the variables stay inside the loop. Eg.

for(int i=0; i<5; i++)
{
    do stuff;
}

i+=1  // raises error as i is not initialised.

where as the same code works in python

for i in range(5)
    do stuff

i+=1  # doesn't raise error as i is initialised.

Though this can be helpful at times, sometimes it is a pain as even though rarely I use variable names like i, key, value yet again in the code after the loop without facing any explicit error.

Is there a more pythonic way than using del i after the loop to avoid the above issues?

EDIT: This question has been marked duplicate of Short description of the scoping rules? which I had seen ages ago. That thread describes how scoping works in python whereas my question is totally different. Please unmark this as a duplicate.

If your methods are complex enugh that you worry about this, perhaps the fix is to write simpler methods. — tripleee, Mar 26 '19 at 06:22
@kevinkayaks wrapping every loop in a function seems a bit too untidy, isn't it? anything pythonic will be appreciated. :) — markroxor, Mar 26 '19 at 06:27
The pythonic way is that variables can be used after th loop, IMHO — handras, Mar 26 '19 at 06:41
Possible duplicate of [Short description of the scoping rules?](https://stackoverflow.com/questions/291978/short-description-of-the-scoping-rules) — handras, Mar 26 '19 at 06:43
proposal for for-loop variable scope https://mail.python.org/pipermail/python-ideas/2008-October/002109.html — paradox, Mar 26 '19 at 06:49
Every comment is missing the line - `Is there a more pythonic way than using del i after the loop to avoid the above issues?` . I would gladly accept the answer which says - "no there is no such way" without being rude, if that is true. — markroxor, Mar 27 '19 at 02:13

greentec · Answer 1 · 2019-03-26T06:43:29.267

0

In Python3, list comprehension may be one answer...?

[print(i) for i in range(5)]
print(i)

>> 0
1
2
3
4

---------------------------------------------------------------------------
NameError Traceback (most recent call last)
<ipython-input-1-598b4fd0c0c5> in <module>()
1 [print(i) for i in range(5)]
----> 2 print(i)

NameError: name 'i' is not defined

edited Mar 26 '19 at 06:43

answered Mar 26 '19 at 06:36

greentec

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I am aware of list comprehensions. My loops are not nearly as simple as this. – markroxor Mar 27 '19 at 02:06

Auto destruct variables after loop scope-end

1 Answers1