title: Mapping UK Postcodes to Geographic boundaries for plotting
body: <p>I have a dataframe with a (UK) postcode column, and a count column, e.g.</p>
  <pre class="lang-py prettyprint-override"><code>postcode  count
  SW1W0NY   10
  PO167GZ   22
  GU167HF   15
  L18JQ     38
  </code></pre>
  <p>I wish to create a heatmap of this data using <code>folium</code>, where the counts are aggregated as per larger (e.g. county-level) geographic polygons.</p>
  <p>There are several <a href="https://www.freemaptools.com/download-uk-postcode-lat-lng.htm" rel="nofollow noreferrer">online resources</a> which map postcodes to lat/long, but is there any python library or resource which maps postcodes to larger UK geographic regions (e.g. county level)?</p>