Python: Int not iterable error

Question

I'm attempting to get my feet wet with python on Project Euler, but I'm having an issue with the first problem (find the sum of the multiples of 3 or 5 up to 1,000). I can successfully print out multiples of three and five, but when I attempt to include the sum function I get the following error:

TypeError: 'int' object is not iterable

Any help would be appreciated.

n = 100
p = 0
while p<n:
   p = p + 1
x = range(0, p)

# check to see if numbers are divisable by 3 or 5
def numcheck(x): 
   for numbers in x:
      if numbers%3==0 and numbers%5==0:
          sum(numbers)
numcheck(x)

Answer 1

In the for-loop

for numbers in x:

"numbers" steps through the elements in x one at a time, for each pass through the loop. It would be perhaps better to name the variable "number" because you are only getting one number at a time. "numbers" equals an integer each time through the loop.

sum(numbers)

throws a TypeError because the function sum() expects an iterable object (like a list of numbers), not just one integer.

So perhaps try:

def numcheck(x):
    s=0
    for number in x:
        if number%3==0 and number%5==0:
            s+=number
    print(s)
numcheck(range(1000))

Answer 2

numbers needs to be a list or similar when it is passed to sum(). In the code example above, it is an integer - one of the integers from x.

Try something like:

numbers = [num for num in x if num%3==0 and num%5 ==0]
print sum(numbers)

Answer 3

The sum function expects a list, not a single number.

When you do for numbers in, then the variable numbers has a single integer object. Add a print statement, you'll see that numbers is a single number.

You might want to accumulate all the multiples of 3 and 5 in a list. Once you have the list, you can then use the sum function on that list.