title: How to sort a list with struct data in python like this?
body: <p>I define a struct by class like this:</p>
  
  <pre><code>  class image:
    def __init__(self):
        self.address = ''
        self.label = 1
        self.storage = 1
  </code></pre>
  
  <p>Then, I put 100 stuct data into one list.</p>
  
  <pre><code>images = []
  for i in range(100):
      single_image = image()
      single_image.address = 'xxx'
      single_image.label = 3 #1:5
      single_image.storage = 10 #1:100
  </code></pre>
  
  <p>How can I sort images by the storage?</p>