title: pandas group by remove outliers
body: <p>I want to remove outliers based on percentile 99 values by group wise. </p>
  
  <pre><code> import pandas as pd
   df = pd.DataFrame({'Group': ['A','A','A','B','B','B','B'], 'count': [1.1,11.2,1.1,3.3,3.40,3.3,100.0]})
  </code></pre>
  
  <p>in output i want to remove 11.2 from group A and 100 from group b. so in final dataset there will only be 5 observations.</p>
  
  <pre><code>wantdf = pd.DataFrame({'Group': ['A','A','B','B','B'], 'count': [1.1,1.1,3.3,3.40,3.3]})
  </code></pre>
  
  <p>I have tried this one but I'm not getting the desired results</p>
  
  <pre><code>df[df.groupby("Group")['count'].transform(lambda x : (x&lt;x.quantile(0.99))&amp;(x&gt;(x.quantile(0.01)))).eq(1)]
  </code></pre>