title: Is it possible to delete/downgrade python packages from Google Colab?
body: <p>I'm using Google Colab, to test Keras models. A library I'm using (hyperopt) seems to misbehave with another library with a specific version (networkx == 2.1). It was mentioned that the latest version of hyperopt on the master branch of its repository has solved this problem, but it isn't working in my case.</p>
  
  <p>I tried <code>!pip uninstall networkx</code>, followed by <code>!pip install networkx==1.11</code>, finally checking the version with </p>
  
  <pre><code>    import network x
      print(networkx.__version__)
  </code></pre>
  
  <p>Which still prints 2.1</p>
  
  <p>Is it not possible to downgrade a package in Google Colab?</p>
  
  <p>Error is similar to this: <a href="https://github.com/hyperopt/hyperopt/pull/319" rel="noreferrer">https://github.com/hyperopt/hyperopt/pull/319</a></p>
  
  <p>Running Python 3.</p>