title: Python3: how to import antlr4
body: <p>I'm trying to import antlr4 into a python3 code but I obtain the error:</p>
  
  <pre><code>$ python3 test.py
  Traceback (most recent call last):
    File "test.py", line 3, in &lt;module&gt;
      import antlr4
  ImportError: No module named 'antlr4'
  </code></pre>
  
  <p>I precise that antlr4 is already present in my computer:</p>
  
  <pre><code>$ antlr4
  ANTLR Parser Generator  Version 4.5.1
   -o ___              specify output directory where all output is generated
   -lib ___            specify location of grammars, tokens files
  ...
  </code></pre>
  
  <p>I tryed with 2 little tests too, test.py works: </p>
  
  <pre><code>#!/usr/bin/python3
  import os, re, sys
  print('test')
  </code></pre>
  
  <p>but this version doesn't:</p>
  
  <pre><code>#!/usr/bin/python3
  import os, re, sys
  import antlr4
  print('test')
  </code></pre>
  
  <p>How can I connect this antlr4 module with python, please?
  Thanks in advance</p>