title: If I import a package into python, do I also have to important it's modules separately?
body: <p>Very simply, I'm reasonably new to coding, and I'm going through another person's code to understand what it is doing as I have to use it for data analysis but I notice that they do the following:</p>
  
  <pre><code> import matplotlib.pyplot as plt
  .
  .
  .
  import matplotlib as mpl
  import numpy as np
  .
  .
  import matplotlib.ticker
  </code></pre>
  
  <p>I thought that "<code>import matplotlib as mpl</code>" would import all modules contained in matplotlib and therefore there need to separately import the module "<code>ticker</code>" from matplotlib after this? I would have thought that they could just use <code>"mpl.ticker"</code> later on and it would work?</p>
  
  <p>Why would this be the case?</p>