CODEWITHSUNDEEP
python
jpotty
jpotty

Reputation: 31

Python adding Integers in a string

Im getting the error:

>>> sum_digits(123)
Traceback (most recent call last):
  File "<pyshell#16>", line 1, in <module>
    sum_digits(123)
  File "D:/Python/Final/#4.py", line 4, in sum_digits
    for i in n:
TypeError: 'int' object is not iterable
>>> 

def sum_digits(n):
   s = 0
   for i in n:
      s += n 
return s

Upvotes: 2

Views: 363

Answers (4)

Padraic Cunningham
Padraic Cunningham

Reputation: 180401

You cannot iterate over an int but you can still do it without casting to str:

def sum_digits(n):
    n, i = divmod(n, 10)
    while n:
        n, r = divmod(n, 10)
        i += r
    return i

Demo:

In [2]:  sum_digits(123456789)
Out[2]: 45

In [3]:  sum_digits(123)
Out[3]: 6

In [4]:  sum_digits(100)
Out[4]: 1

It does not make much sense to convert from int to str then back to int again.

Upvotes: 0

timgeb
timgeb

Reputation: 78690

The problem here is that your are passing an int to your function, which you cannot iterate over.

I suggest the solution

>>> n = 123
>>> sum(int(x) for x in str(n))
6

Upvotes: 2

Scott Hunter
Scott Hunter

Reputation: 49803

If you want i to range over the digits of n, you'd need something like:

for i in [int(x) for x in str(n)]:

Or, you could just pass "123" instead of 123 to sum_digits, which the title of your post suggests is what you actually mean to do. Of course, then you'd need to convert each character to its numeric value.

Upvotes: 0

falsetru
falsetru

Reputation: 369064

You need to convert the number to str (not int) and iterate it:

def sum_digits(n):
   s = 0
   for i in str(n):
      s += int(i)
   return s

usage:

>>> sum_digits(123)
6

Using sum and generator expression:

def sum_digits(n):
    return sum(int(i) for i in str(n))
    # OR  return sum(map(int, str(n)))

Upvotes: 2

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