title: Selecting with complex criteria from pandas.DataFrame
body: <p>For example I have simple DF:</p>
  <pre><code>import pandas as pd
  from random import randint
  
  df = pd.DataFrame({'A': [randint(1, 9) for x in range(10)],
                     'B': [randint(1, 9)*10 for x in range(10)],
                     'C': [randint(1, 9)*100 for x in range(10)]})
  </code></pre>
  <p>Can I select values from 'A' for which corresponding values for 'B' will be greater than 50, and for 'C' - not equal to 900, using methods and idioms of Pandas?</p>