ImportError: No module named 'ase.build'
<p>In ubuntu 16.04 i installed python and modules:</p>

<pre><code>sudo apt install python3 python3-scipy python3-numpy python3-ase
</code></pre>

<p>then i try to follow <a href="https://wiki.fysik.dtu.dk/ase/tutorials/surface.html" rel="nofollow">the first tutorial</a> on the <a href="https://wiki.fysik.dtu.dk/ase/index.html" rel="nofollow">ASE homepage</a>. I run <code>python3</code> in <code>bash</code> terminal, and can import other modules but not <code>ase-build</code>. It looks like this: </p>

<pre><code>&gt;&gt;&gt; from ase.optimize import QuasiNewton
&gt;&gt;&gt; from ase.build import fcc111, add_adsorbate
Traceback (most recent call last):
  File "&lt;stdin&gt;", line 1, in &lt;module&gt;
ImportError: No module named 'ase.build'
&gt;&gt;&gt; 
</code></pre>

<p>Using a python script throws an equivalent error. 
What could be the problem? </p>

<p><strong>UPDATE &amp; SOLUTION</strong> 
Seems this was not really even a python problem. I seem to have had some package dependency errors probably due to not running <code>apt update</code> in a long time between program installations. I removed <code>python2.x</code> and <code>python 3.x</code>, then iterated <code>apt update</code>, <code>apt upgrade</code>, <code>apt autoremove</code>, then reinstalled only <code>python3</code>. I installed <code>python3-pip</code> and installed the numpy, scipy, and ase packages using the proper form <code>python3 -m pip install --upgrade &lt;package&gt;</code>. Now everything works as expected. </p>