(python) can not access variables inside of a for loop to use it elsewhere

Question

I am trying to make a python script that calculates the standart deviation of numbers in a list

    for i in listofnums:
        total += (i - sumofnums) ** 2


    result = math.sqrt(total / (len(listofnums) -1))

This is the part of the program that I'm having issues with, I cannot use the total variable for getting the result for the result variable

    total += (i - sumofnums) ** 2
    NameError: name 'total' is not defined

Nearly every tutorial/documentation I looked at, it shows that you can access variables like total outside the for loop

Am I doing something stupid here?

Why do you say the variable cannot be accessed? Is there a traceback? — S3DEV, May 29 '22 at 07:14
A possible scenario where the variable total won't be created is if you didn't initialize it before the for-loop and there were 0 loops. — shai gindin, May 29 '22 at 07:26

score -1 · Answer 1 · answered May 29 '22 at 07:27

with that said, doing something this simple would help:

total=0 #just add it here
for i in listofnums:
        total += (i - sumofnums) ** 2


result = math.sqrt(total / (len(listofnums) -1))

1 Answers1