title: IPython print output is broken
body: <p>I installed Jupyter and Ipython in a virtual environment. Whenever I type something in the IPython REPL and press enter, the output is prepended with a bunch of repeated garbage:</p>
  <pre class="lang-py prettyprint-override"><code>In [2]: print(&quot;Hello, world!&quot;)
  </code></pre>
  <pre class="lang-py prettyprint-override"><code>
  line='print(&quot;Hello, world!&quot;)\n', last_line=b'', encoding=None
  print
  (
  &quot;Hello, world!&quot;
  )
  
  
  line=b'', last_line='print(&quot;Hello, world!&quot;)\n', encoding=None
  
  line='print(&quot;Hello, world!&quot;)\n', last_line=b'', encoding=None
  print
  (
  &quot;Hello, world!&quot;
  )
  
  
  line=b'', last_line='print(&quot;Hello, world!&quot;)\n', encoding=None
  
  line='print(&quot;Hello, world!&quot;)\n', last_line=b'', encoding=None
  print
  (
  &quot;Hello, world!&quot;
  )
  
  
  line=b'', last_line='print(&quot;Hello, world!&quot;)\n', encoding=None
  Hello, world!
  </code></pre>
  <pre><code>In [3]: 2 + 2
  </code></pre>
  <pre><code>line='2 + 2\n', last_line=b'', encoding=None
  2
  +
  2
  
  
  line=b'', last_line='2 + 2\n', encoding=None
  
  line='2 + 2\n', last_line=b'', encoding=None
  2
  +
  2
  
  
  line=b'', last_line='2 + 2\n', encoding=None
  
  line='2 + 2\n', last_line=b'', encoding=None
  2
  +
  2
  
  
  line=b'', last_line='2 + 2\n', encoding=None
  
  line='2 + 2', last_line=b'', encoding=None
  2
  +
  2
  line='', last_line='2 + 2', encoding=None
  Out[3]: 4
  </code></pre>
  <p>This garbage output occurs in both IPython REPL in a terminal, and Jupyter notebooks in a browser.</p>
  <p>I'm running Windows 10 with Python 3.8.1. The package versions are:</p>
  <ul>
  <li>jupyter 1.0.0</li>
  <li>ipython 7.17.0</li>
  <li>notebook 6.1.1</li>
  </ul>
  <p>These were installed via Poetry. I installed the exact same Python and package versions on a separate PC (running Linux) and the problem did not appear, so I suspect something is configured wrong on my Windows PC rather than the problem being a bug in IPython.</p>
  <p>How do I make it print like normal again?</p>