title: Checking if an ISBN Book Number is valid Python
body: <p>So I have been trying to convert this 'validator' from Pseudocode to Python, but I'm not too sure if my values are being put into a list. After I enter the first value, an error appears saying: <code>'int' object is not callable</code>. But then if I get rid of <code>isbn = mylist()</code>, it says that <code>name 'isbn' is not defined</code>. Can someone point me out where my mistake is?</p>
  
  <p>I'm pretty sure I'm not setting up my list correctly.</p>
  
  <p>Here is the PSEUDOCODE I'm following:</p>
  
  <p><a href="https://i.stack.imgur.com/mA57s.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/mA57s.png" alt="enter image description here"></a></p>
  
  <p>And my code:</p>
  
  <pre><code>def checkDigit():
      calculateDigit = 0
      count = 1
      calculateDigit = 10 - calculateDigit
      for count in range (1,14):
          mylist = int(input("Please enter the next digit of the ISBN: "))
   #      isbn = mylist()
      while (count &lt;= 13):
          calculateDigit = calculateDigit + isbn[count]
          count = count + 1
          calculateDigit = calculateDigit + (isbn[count] * 3)
          count = count + 1
      while (calculateDigit &gt;= 10):
          calculateDigit = calculateDigit - 10
      if (calculateDigit == 10):
          calculateDigit = 0
      if (calculateDigit == isbn[13]):
          print ("Valid ISBN")
      else:
          print ("Invalid ISBN")
  
  
  
  checkDigit()
  </code></pre>