title: pandas make blank line between merges files
body: <p>how can i remove the blank line in line 6 and 7?
  it just happens when i merge value 1 and value 2, with value 3 everything is fine.
  <a href="https://i.stack.imgur.com/fxvy9.png" rel="nofollow noreferrer">enter image description here</a></p>
  <pre><code>
  ListOri = 'Blocked_Persons_List_original.xls'
  NG = 'NG.xlsx'
  MB = 'MB.xlsx'
  
  
  df1 = pd.read_excel(ListOri)
  df2 = pd.read_excel(NG)
  df3 = pd.read_excel(MB)
  
  
  values1 = df1[[&quot;Unique ID&quot;,&quot;Name&quot;,&quot;Street of residence&quot;,&quot;City of residence&quot;,&quot;Country of residence&quot;,&quot;Date of birth&quot;,&quot;Place of birth&quot;,&quot;Country of birth&quot;,&quot;Citizenship&quot;,&quot;Account number/ IBAN&quot;,&quot;BIC Code&quot;,&quot;Source&quot;,&quot;Notice&quot;,&quot;Reserve 1&quot;,&quot;Reserve 2&quot;,&quot;Amount EURO&quot;,&quot;Currency&quot;]]
  values2 = df2[[&quot;Name&quot;,&quot;Account number/ IBAN&quot;,&quot;BIC Code&quot;,&quot;Notice&quot;]]
  values3 = df3[[&quot;Account number/ IBAN&quot;,&quot;BIC Code&quot;,&quot;Notice&quot;,&quot;Reserve 1&quot;,&quot;Reserve 2&quot;]]
  
  
  dataframes = [values1, values2, values3]
  
  
  
  
  join = pd.concat(dataframes,ignore_index = True)
  
  join.to_excel(&quot;output.xlsx&quot;)```
  </code></pre>