title: Hot to transform multiple dataframes to specific format?
body: <p>i have two dataframes:</p>
  
  <pre><code>df1 = pd.DataFrame(
      {
        "database": {
          "0": "database1",
          "1": "database1",
          "2": "database1",
        },
        "table": {
          "0": "table A",
          "1": "table B",
          "2": "table C",
        },
        "node": {
          "0": "node1",
          "1": "node1",
          "2": "node1",
        },
        "value": {
          "0": "A1",
          "1": "B1",
          "2": "C1",
        }
      })
  
  
  df2 = pd.DataFrame(
      {
        "database": {
          "0": "database1",
          "1": "database1",
          "2": "database1",
        },
        "table": {
          "0": "table B",
          "1": "table C",
          "2": "table D",
        },
        "node": {
          "0": "node2",
          "1": "node2",
          "2": "node2",
        },
        "value": {
          "0": "B2",
          "1": "C2",
          "2": "D2",
        }
      })
  df2
  
  df1
      database    table   node    value
  0   database1   table A node1   A1
  1   database1   table B node1   B1
  2   database1   table C node1   C1
  
  df2
      database    table   node    value
  0   database1   table B node2   B2
  1   database1   table C node2   C2
  2   database1   table D node2   D2
  </code></pre>
  
  <p>How to transform these two dataframes to this format?</p>
  
  <p><a href="https://i.stack.imgur.com/ZDeJj.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ZDeJj.png" alt="enter image description here"></a></p>
  
  <p>Stackoverflow doesn't allow me to submit the question due: "It looks like your post is mostly code; please add some more details.".
  I added this text just to pass further.</p>