title: join two dataframes with same column name consecutively?
body: <p>Input:</p>
  
  <pre><code>df = pd.DataFrame({"A":["foo", "foo", "foo", "bar"],"B":[0,1,1,1]})
  
  
     df1 = pd.DataFrame({"A":["Panda", "Panda", "Zootopia", "Zootopia"],"B":[0,1,1,1]})
  </code></pre>
  
  <p>Output:</p>
  
  <pre><code>     A          B
  0   foo         0
  1   foo         1
  2   foo         1
  3   bar         1
  4   Panda       0
  5   Panda       1
  6   Zootopia    1
  7   Zootopia    1
  </code></pre>
  
  <p>Join df and df1 like given in the expected output.</p>