title: Using a for loop to add values in a list
body: <p>I am new to Python and am having trouble wrapping my head around why this doesn't work. </p>
  
  <pre><code>number_string = input("Enter some numbers: ")
  
  # Create List
  number_list = [0]
  
  # Create variable to use as accumulator
  total = 0
  
  # Use for loop to take single int from string and put in list
  for num in number_string:
      number_list.append(num)
  
  # Sum the list
  for value in number_list:
      total += value
  
  print(total)
  </code></pre>
  
  <p>Basically, I want a user to enter 123 for example and then get the sum of 1 and 2 and 3. </p>
  
  <p>I am getting this error and do not know how to combat it. </p>
  
  <pre><code>Traceback (most recent call last):
    File "/Users/nathanlakes/Desktop/Q12.py", line 15, in &lt;module&gt;
      total += value
  TypeError: unsupported operand type(s) for +=: 'int' and 'str'
  </code></pre>
  
  <p>I just can't find the answer to this in my textbook and don't understand why my second for loop won't iterate the list and accumulate the value to total.</p>