title: Overwrite global variables
body: <p>I have two modules:</p>
  
  <p><strong>constants.py</strong></p>
  
  <pre><code>def define_sizes(supersample):    
      global SUPERSAMPLE
      global WIDTH
      global HEIGHT
      global LINE_WIDTH
  
      SUPERSAMPLE = supersample
      WIDTH = 1280*SUPERSAMPLE
      HEIGHT = 854*SUPERSAMPLE
      LINE_WIDTH = 1*SUPERSAMPLE
  
  define_sizes(1)
  </code></pre>
  
  <p><strong>test.py</strong></p>
  
  <pre><code>from constants import *
  
  
  print(WIDTH, HEIGHT, LINE_WIDTH)
  # Draw something
  
  define_sizes(4)
  
  print(WIDTH, HEIGHT, LINE_WIDTH)
  # Draw the same thing, but bigger
  </code></pre>
  
  <p>The result is:</p>
  
  <pre><code>1280 854 1
  1280 854 1
  </code></pre>
  
  <p>I would expect to get:</p>
  
  <pre><code>1280 854 1
  5120 3416 4
  </code></pre>
  
  <p>Why is that? What am I missing? Can I fix it to give expected results?</p>