title: Filtering in pandas dataframe is not working
body: <p>I'm trying to combine 3 CSV into one by using panda data frame. Consider below example</p>
  <p><a href="https://i.stack.imgur.com/oG28i.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/oG28i.png" alt="data1.csv" /></a>
  <a href="https://i.stack.imgur.com/Im0re.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Im0re.png" alt="data2.csv" /></a>
  <a href="https://i.stack.imgur.com/CFUKO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/CFUKO.png" alt="data3.csv" /></a></p>
  <p>So I need to combine above the csv into one. This is implemented using below code</p>
  <pre><code>if os.path.isfile(data1.csv) and os.path.isfile(data2.csv) and os.path.isfile(data3.csv):
      df1 = pd.read_csv(data1.csv)
      df2 = pd.read_csv(data2.csv)
      df3 = pd.read_csv(data3.csv)
      self.combined_data_frame = pd.concat([df1, df2, df3], ignore_index=True)
      self.combined_data_frame = pd.DataFrame(self.combined_data_frame, columns=['col1', 'col2', 'col3'])
      result = self.combined_data_frame.loc[(self.combined_data_frame['col3'] == 'FALSE')]
      result.to_csv(data4.csv)
  </code></pre>
  <p>Even though am able to combine the CSV into one, could not filter the rows based on the condition. When I tried above code snippet I got below warning and data4.csv does not contain anything except the headers</p>
  <pre><code>(venv) C:\Users\edward_arrow\path_to_location&gt;python runscript.py
  C:\Users\edward_arrow\path_to_location\venv\lib\site-packages\pa
  ndas\core\computation\expressions.py:68: FutureWarning: elementwise comparison f
  ailed; returning scalar instead, but in the future will perform elementwise comp
  arison
    return op(a, b)
  </code></pre>
  <p>May I know how can I resolve this issue in order to achieve my requirement or else is there any other method to implement using python.</p>
  <p>Your  hints &amp; solution are appreciated
  #UPDATE
  This is the excepted output
  <a href="https://i.stack.imgur.com/kBH5e.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/kBH5e.png" alt="final output" /></a></p>