title: How to divide two columns element-wise in a pandas dataframe
body: <p>I have two columns in my pandas dataframe. I'd like to divide column <code>A</code> by column <code>B</code>, value by value, and show it as follows:</p>
  <pre><code>import pandas as pd
  
  csv1 = pd.read_csv('auto$0$0.csv')
  csv2 = pd.read_csv('auto$0$8.csv')
  
  df1 = pd.DataFrame(csv1, columns=['Column A', 'Column B'])
  df2 = pd.DataFrame(csv2, columns=['Column A', 'Column B'])
  
  dfnew = pd.concat([df1, df2])
  </code></pre>
  <p>The columns:</p>
  <pre><code>Column A  Column B
  12        2
  14        7
  16        8
  20        5
  </code></pre>
  <p>And the expected result:</p>
  <pre><code>Result
  6
  2
  2
  4
  </code></pre>
  <p>How do I do this?</p>