title: Populating a function argument with user input in Python
body: <p>I'm trying to create a piece of code that performs simple subtraction and prints a message based on the user's input, but I haven't been able to figure out how to get the user input to properly serve as the functions argument.</p>
  <p>I keep getting the following error, even though I've included int along with the user input:</p>
  <blockquote>
  <p>TypeError: '&gt;=' not supported between instances of &gt; 'NoneType' and 'int'</p>
  </blockquote>
  <p>Do you have any clue what I'm missing?</p>
  <p>The exact code I'm working on shown below:</p>
  <pre><code>def withdraw_money(current_balance, amount):
      if (current_balance &gt;= amount):
          current_balance = current_balance - amount
          return current_balance
  
  balance = withdraw_money(int(input(&quot;How much money do you have&quot;)), int(input(&quot;How much do your groceries cost&quot;)))
  
  if (balance &gt;= 0): 
      print(&quot;You're good&quot;)
  else: 
      print(&quot;You're broke&quot;)
  </code></pre>