title: Extracting specific columns from pandas.dataframe
body: <p>I'm trying to use python to read my csv file extract specific columns to a <code>pandas.dataframe</code> and show that dataframe. However, I don't see the data frame, I receive Series([], dtype: object) as an output. Below is the code that I'm working with:
  My document consists of: 
       product    sub_product issue   sub_issue   consumer_complaint_narrative<br>
       company_public_response    company state   zipcode tags<br>
       consumer_consent_provided  submitted_via   date_sent_to_company<br>
       company_response_to_consumer   timely_response consumer_disputed?<br>
       complaint_id</p>
  
  <p>I want to extract :
       sub_product    issue   sub_issue   consumer_complaint_narrative</p>
  
  <pre><code>import pandas as pd
  
  df=pd.read_csv("C:\\....\\consumer_complaints.csv")
  df=df.stack(level=0)
  df2 = df.filter(regex='[B-F]')
  df[df2]
  </code></pre>