Sum of odd numbers in a range

Question

What is the sum of the odd numbers from 1523 through 10503, inclusive? Hint: write a while loop to accumulate the sum and print it. Then copy and paste that sum. For maximum learning, do it with a for loop as well, using range.

What I tried. I need to print the sum as a total. My answer gives me the individual runs.

i=1523
while i<10503:
    sum=0
    i=i+2
    sum=sum+i
    print(sum)


for i in range(1523,10503):
    print(i+2)

Make sure to format your code correctly when posting. Whitespace is important in Python. — voithos, Aug 01 '13 at 23:36
I may be reading your requirement wrong, but it seems like the `sum=0` should go outside the loop. — Troy, Aug 01 '13 at 23:37
Hint: an odd number is equal to 1 modulo 2; i.e. 3 % 2 == 1. — squiguy, Aug 01 '13 at 23:38
Quick note guys, don't use `sum` because it's a python builtin. — Snakes and Coffee, Aug 01 '13 at 23:41
Maybe not "don't use `sum`", but "avoid using `sum`". It is not a law carved in stone. — Hyperboreus, Aug 01 '13 at 23:43

Hyperboreus · Accepted Answer · 2013-08-01T23:45:23.237

9

You assignment says "inclusive", hence you should include 10503 into the sum:

i = 1523
total = 0
while i <= 10503:
    total += i
    i += 2
print (total)

total = 0
for i in range (1523, 10504, 2):
    total += i
print (total)

Also avoid using builtin names, like sum. Hence I changed it to total.

On a side note: Although your assignment asks explicitely for control statements, you (or at least I) would implement it as:

print (sum (range (1523, 10504, 2) ) )

edited Aug 01 '13 at 23:45

answered Aug 01 '13 at 23:38

Hyperboreus

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Amazing comprehensive answer for how concise it is. Of course there's no `reduce` over a mutating `__iadd__` method on a wrapper around a `ctypes.c_int`… :) – abarnert Aug 02 '13 at 00:28

score 0 · Answer 2 · edited Apr 18 '15 at 15:28

0

As Troy said, put the sum=0 before the loop. Then put print(sum) after the while loop.

edited Apr 18 '15 at 15:28

Magnilex

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answered Aug 01 '13 at 23:40

TheDoctor

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I think he wasn't adding the last number since the assignment says inclusive – Saher Ahwal Aug 02 '13 at 00:45

Sum of odd numbers in a range

2 Answers2