title: Multiply a column with a row
body: <p>I have a data frame like this</p>
  <pre><code>Name        Oil     Cream      Sales
  A           0        900        43
  B          12         0         76
  C           0         9         48
  D           3         0         33
  E          12        98         91
  Cur Sales  0.1       0.9       998
  </code></pre>
  <p>Now when I want to make this into a data frame something like when the value is 0 then I has to multiply for oil column 43 * 0.1 on A row, for a cream column on 0 (76 * 0.9) on B row and for Oil column on C row on 0 (48 * 01). Something like that.</p>
  <p>Expected Output</p>
  <pre><code>Name       Oil     Cream      Sales
  A          4.3                 43
  B                   68.4       76
  C          4.8                 48
  D                   29.7       33
  E                              91
  Cur Sales  0.1      0.9       998
  </code></pre>
  <p>For numbers that are greater than 0 I did</p>
  <pre><code>df[df &gt; 0] = &quot; &quot;
  </code></pre>
  <p>Which makes them blank but how do I multiply column value with row on that particular 0?</p>