title: Conversion of row elements in a column in pandas dataframe
body: <p>Problem :</p>
  <pre><code>                               df['bua']          
                        
                        0        Built-up Area 97 Sq Yards
                        1        Built-up Area 85 Sq Yards
                        2        Built-up Area 80 Sq Yards
                        3       Built-up Area 100 Sq Yards
                        4        Built-up Area 87 Sq Yards
                                            ...            
                        1832     Built-up Area 73 Sq Yards
                        1833     Built-up Area 80 Sq Yards
                        1834     Built-up Area 82 Sq Yards
                        1835    Built-up Area 1500 Sq Feet
                        1836     Built-up Area 66 Sq Yards
                        Name: bua, Length: 1837, dtype: object
  </code></pre>
  <p>I need to convert each of the above elements of the column 'bua' into square feet.
  Also remove  the 'Built-up Area','Feet','Yards' at the end.</p>
  <p>Output :</p>
  <p>The output should look like</p>
  <pre><code>                                   df['bua']
                          
                            0        XX97         ^
                            1        XX85         |
                            2        XX80         | 
                            3        XX10         | # Values in sq-feet after conversion
                            4        XX87         | 
                                     ...          |   
                            1832     XX73         |
                            1833     XX80         | # Values in sq-feet after conversion
                            1834     XX82         |
                            1835     XX15         |
                            1836     XX66         V
                            Name: bua, Length: 1837, dtype: object
  </code></pre>