title: normalization misses polish characters
body: <p>I have a big dataframe with people data. I would like to flatten all weird diacritics and convert them to the closest ascii character. Based on a solution I found in SO I do the following:</p>
  
  <pre><code>for column in df.columns:
              df[column] = df[column].astype("str").str.normalize('NFKD').str.encode('ascii', errors='ignore').str.decode('utf-8')
  </code></pre>
  
  <p>It works for most of the cases (haven't checked them all) however I have noticed it misses letter 'ł' in Polish. For example <code>Lech Wałęsa</code> is translated to <code>Lech Waesa</code> while my expectation would be to see <code>Lech Walesa</code>. My guess would be that it's what <code>ignore</code> parameter does in <code>str.encode</code> method. Any idea how to make it work for any  diacritic? </p>