title: How to solve the performance warning while adding a dataframe in list in a for loop?
body: <p>I have created a for loop and i am getting a dataframe(given below) as an output. I am appending every outputs to a blank list. I am getting the outputs but with an performance warning as:</p>
  <h1>PerformanceWarning: Adding/subtracting array of DateOffsets to Series not vectorized</h1>
  <p>output dataframe:</p>
  <p>Intercept     Slope
  0   3.008165 -0.001024
  Intercept     Slope
  0   2.153798  0.001749</p>
  <p>Code:</p>
  <pre><code>coeff = []
  
  for x in something:
      #do something
      reg_df = DataFrame({&quot;Slope&quot;:slope,&quot;Intercept&quot;:intercept})
      coeff.append(reg_df)
  </code></pre>
  <p>Why i am getting that Warning ?</p>
  <p>How can i solve this?</p>
  <p>Any help would be appreciated.</p>