title: Unalignable boolean Series provided as indexer (index of the boolean Series and of the indexed object do not match)
body: <p>I guess I know why I am getting this error. It's because the inner list does not match the outer list. It just did not click on how to deal with this problem</p>
  <p>The code is pretty easy
  I got data frame df which has many columns. I want to drop all columns that have more than 70% zero data however that rule will have to apply for columns after column 22.</p>
  <p>df = df.loc[:, (df.iloc[:, 22:]==0).mean() &lt; 0.7]</p>