Python - TypeError: 'int' object is not iterable

If the case is:

n=int(input())

Instead of -> for i in n: -> gives error- int object is not iterable

Use -> for i in range(0,n):works fine..!

This is very simple you are trying to convert an integer to a list object !!! of course it will fail and it should ...

To demonstrate/prove this to you by using the example you provided ...just use type function for each case as below and the results will speak for itself !

>>> type(cow)
<class 'range'>
>>> 
>>> type(cow[0])
<class 'int'>
>>> 
>>> type(0)
<class 'int'>
>>> 
>>> >>> list(0)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'int' object is not iterable
>>> 

Your problem is with this line:

number4 = list(cow[n])

It tries to take cow[n], which returns an integer, and make it a list. This doesn't work, as demonstrated below:

>>> a = 1
>>> list(a)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'int' object is not iterable
>>>

Perhaps you meant to put cow[n] inside a list:

number4 = [cow[n]]

See a demonstration below:

>>> a = 1
>>> [a]
[1]
>>>

---

Also, I wanted to address two things:

1. Your while-statement is missing a : at the end.
2. It is considered very dangerous to use input like that, since it evaluates its input as real Python code. It would be better here to use raw_input and then convert the input to an integer with int.

---

To split up the digits and then add them like you want, I would first make the number a string. Then, since strings are iterable, you can use sum:

>>> a = 137
>>> a = str(a)
>>> # This way is more common and preferred
>>> sum(int(x) for x in a)
11
>>> # But this also works
>>> sum(map(int, a))
11
>>>