title: Generating random number for class attribute
body: <p>I have the following code:</p>
  
  <pre><code>from numpy import random
  
  class Person():
  
      def __init__(self, name, age=random.randint(18,65)):
          self.name = name
          self.age = age
  </code></pre>
  
  <p>I want age to be a random number between 18 and 65, unless explicitly specified. However, when I create different instances of this class, like so:</p>
  
  <pre><code>p1 = Person('Bob')
  p2 = Person('Sue')
  p3 = Person('Jeff')
  </code></pre>
  
  <p>Each person always have the same age. How can I fix this?</p>