title: Failed to import dataclasses module
body: <p>Today I installed python 3.7 from apt-get to try out the new dataclasses module. I installed it seperately because python3.6 wasn't upgradeable to 3.7.</p>
  
  <p>When I type: <code>python3.7 --version</code>, it gives me: <code>&gt;&gt;&gt; Python 3.7.0a2</code> as my current version.</p>
  
  <p>The problem is that I can't seem to import dataclasses.</p>
  
  <p>my import statement is: <code>from dataclasses import dataclass</code> as instructed <a href="https://docs.python.org/3/library/dataclasses.html" rel="noreferrer">here</a></p>
  
  <p>This is the error message it's giving me:</p>
  
  <pre><code>Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  ModuleNotFoundError: No module named 'dataclasses'
  Error in sys.excepthook:
  Traceback (most recent call last):
    File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 63, in apport_excepthook
      from apport.fileutils import likely_packaged, get_recent_crashes
    File "/usr/lib/python3/dist-packages/apport/__init__.py", line 5, in &lt;module&gt;
      from apport.report import Report
    File "/usr/lib/python3/dist-packages/apport/report.py", line 30, in &lt;module&gt;
      import apport.fileutils
    File "/usr/lib/python3/dist-packages/apport/fileutils.py", line 23, in &lt;module&gt;
      from apport.packaging_impl import impl as packaging
    File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 24, in &lt;module&gt;
      import apt
    File "/usr/lib/python3/dist-packages/apt/__init__.py", line 23, in &lt;module&gt;
      import apt_pkg
  ModuleNotFoundError: No module named 'apt_pkg'
  
  Original exception was:
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  ModuleNotFoundError: No module named 'dataclasses'
  </code></pre>
  
  <p>I even tried installing the dataclasses module with pip3: <code>pip3 install dataclasses</code>. Not sure if that's necessary though.</p>
  
  <p>Any suggestion on what might be the problem?</p>
  
  <p>[EDIT] Just tried it with a python3.6 console and it worked fine .. weird.</p>