title: Function missing 1 required positional argument
body: <p>I'm getting this error :</p>
  
  <pre><code>Traceback (most recent call last):
    File "C:/Users/mali03/Desktop/Python/Practice/p2.py", line 18, in &lt;module&gt;
      first.subtraction(1, 2)
  TypeError: subtraction() missing 1 required positional argument: 'y'
  </code></pre>
  
  <p>Here is my calculator class</p>
  
  <pre><code>class calculator:
  
      def __init__(self, x, y):
          self.x = x
          self.y = y
  
      def addition(self, x, y):
          return self.x + self.y
  
      def subtraction(self, x, y):
          if self.x &gt; self.y:
              return self.y - self.x
          else:
              return self.x - self.y
  </code></pre>
  
  <p>I then call subtraction with the following:</p>
  
  <pre><code>first = calculator
  first.subtraction(1, 2)
  </code></pre>