CODEWITHSUNDEEP
pythonexceptiondivide-by-zero
Joshua Ehinger
Joshua Ehinger

Reputation: 1

Catching ZeroDivisionError

In my exception handling, I'm trying to catch ZeroDivisionError's but for some reason, the code is still doing the division by 0 and not bringing back an error. I must be doing something wrong but I can't seem to place it.

I have tried to move the division elsewhere in the function, and move the division error catch as well. 

filename = "numbers.txt"

def main():
    total = 0.0
    number = 0.0
    counter = 0
    average = 0


    #Open the numbers.txt file
    try:
        infile = open(filename, 'r')

        #Read the values from the file
        for line in infile:
            counter = counter + 1
            number = float(line)
            total += number

        average = total / counter

        #Close the file
        infile.close()

    except IOError:
        print('An error occurred trying to read the file', end=' ')
        print(filename, '.', sep='')

    except ValueError:
        print('Non-numeric data found in the file', end=' ')
        print(filename, '.', sep='')

    except Exception as err:
        print('A general exception occurred.')
        print(err)

    except ZeroDivisionError:
        print('Cannot devide by zero.')

    else:
        print('Average:', average)
        print('Processing Complete. No errors detected.')




# Call the main function.
main()

I'm expecting the result to return the error message when dividing by zero, but it's returning zero as the answer instead.

Upvotes: 0

Views: 12478

Answers (2)

SoulSeeker916
SoulSeeker916

Reputation: 57

It seems like there is no ZeroDivisionError in your file. Because in your for loop, you have incremented counter variable by 1 already. Unless, the for loop is iterating into an empty object.

Hence, your average = total / counter will always start as:

average = total / 1 (since counter = counter + 1)

Hope it helped.

Upvotes: 0

fstop_22
fstop_22

Reputation: 1032

You need to change the order that you catch exceptions. Since all exceptions in Python inherit from the Exception base class, you are never getting the ZeroDivision exception since it is caught by handling of Exception. Try this:

except IOError:
    print('An error occurred trying to read the file', end=' ')
    print(filename, '.', sep='')

except ValueError:
    print('Non-numeric data found in the file', end=' ')
    print(filename, '.', sep='')

except ZeroDivisionError:
    print('Cannot devide by zero.')

except Exception as err:
    print('A general exception occurred.')
    print(err)

else:
    print('Average:', average)
    print('Processing Complete. No errors detected.')

Upvotes: 2

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