title: Select only rows with "True" pandas DataFrame
body: <p>I have to do, maybe a simple thing, but I completely don't know how. I have some code:</p>
  <pre><code>data = df_new.assign(result=df_new['text'].isin(df_oryginal['text']).astype(str))
  df_same = pd.DataFrame(data)
  
  </code></pre>
  <p>and the output is:</p>
  <pre><code>                                                     text  name          index  result
  0                                               some text  filename        0    False
  1                                               some text  filename        1    True
  2                                               some text  filename        2    False
  3                                               some text  filename        3    False
  4                                               some text  filename        4    True
  ...                                                  ...          ...    ...    ...
  36213                                           some text  filename    36213    False
  36214                                           some text  filename    36214    False
  36215                                           some text  filename    36215    True
  </code></pre>
  <p>Now I would like select only these rows where df_same['result'] == True, but I don't know how.
  I have looked all over Google... Please help me, thank you in advance for your answer :)</p>