title: Create a new column multiplying a column and an array with unequal lengths
body: <p>I have the following columns:</p>
  <pre><code>Date                    
  2010-01-04  NaN         NaN         NaN         NaN         NaN
  2010-01-05  0.012724    0.015659    0.000266    0.003344    0.022251
  2010-01-06  0.004910    -0.020427   -0.022870   -0.014700   -0.030640
  2010-01-07  -0.022239   -0.017900   -0.028223   -0.022729   -0.021563
  2010-01-08  0.025978    -0.015153   -0.020648   -0.024394   -0.023600
  ... ... ... ... ... ...
  2021-08-25  -0.000171   -0.003003   0.012596    0.008506    0.001257
  2021-08-26  -0.009339   -0.004284   0.003506    -0.004533   0.011284
  2021-08-27  -0.002833   0.009494    0.013068    -0.011000   -0.003862
  2021-08-30  -0.018293   -0.003945   -0.005080   -0.006311   0.000387
  2021-08-31  0.019848    0.013350    0.022745    0.004935    0.016115
  2875 rows × 5 columns
  </code></pre>
  <p>I am trying to create a new column that will be the sum of multiplication of each row of the columns with respective weights as an output.</p>
  <p>Weights are as follows:</p>
  <pre><code>array([0.12123039, 0.31162947, 0.27817099, 0.10452567, 0.18444348])
  </code></pre>
  <p>For eg.</p>
  <p>On 2010-01-05:</p>
  <p>New column value = (0.012724 * 0.12123039 + 0.015659 * 0.31162947 + 0.000266 * 0.27817099 + 0.003344 * 0.10452567 + 0.022251 * 0.18444348)</p>