title: Python yaml import fails with "NameError: name 'Serializer' is not defined
body: <p>I am using a python script which uses 'yaml'(pyyaml) module to serialise some files. The script was running fine for some time. Lately when I am trying to import yaml in python I am getting the following error:</p>
  <p><a href="https://i.stack.imgur.com/X12Se.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/X12Se.png" alt="Serializer error" /></a></p>
  <p>I am not sure of the origin of the issue, since it is an external package.</p>