title: Convert dictionaries with list of values into a dataframe
body: <p>Say I have three dictionaries</p>
  
  <pre><code>dictionary_col2
  {'MOB': [1, 2], 'ASP': [1, 2], 'YIP': [1, 2]}
  </code></pre>
  
  <pre><code> dictionary_col3
  
  {'MOB': ['MOB_L001_R1_001.gz',
           'MOB_L002_R1_001.gz'],
   'ASP': ['ASP_L001_R1_001.gz',
           'ASP_L002_R1_001.gz'],
   'YIP': ['YIP_L001_R1_001.gz',
           'YIP_L002_R1_001.gz']}
  
  </code></pre>
  
  <pre><code>dictionary_col4
  
  {'MOB': ['MOB_L001_R2_001.gz',
           'MOB_L002_R2_001.gz'],
   'ASP': ['ASP_L001_R2_001.gz',
           'ASP_L002_R2_001.gz'],
   'YIP': ['YIP_L001_R2_001.gz',
           'YIP_L002_R2_001.gz']}
  
  </code></pre>
  
  <p>I wanna convert the above dictionaries into a data frame. I have tried the following,</p>
  
  <p><code>df = pd.DataFrame([dictionary_col2, dictionary_col3, dictionary_col4])</code>
  The <code>df</code> data frame looks like,</p>
  
  <pre><code>                ASP MOB YIP
  0   [1, 2]  [1, 2]  [1, 2]
  1   [ASP_L001_R1_001.gz, ASP_L002_R1_001.gz]    [MOB_L001_R1_001.gz, MOB_L002_R1_001.gz]    [YIP_L001_R1_001.gz, YIP_L002_R1_001.gz]
  2   [ASP_L001_R2_001.gz, ASP_L002_R2_001.gz]    [MOB_L001_R2_001.gz, MOB_L002_R2_001.gz]    [YIP_L001_R2_001.gz, YIP_L002_R2_001.gz]
  </code></pre>
  
  <p>My aim is to have a data frame with the following columns:  </p>
  
  <pre><code>    col1  col2 col3              col4 
      MOB   1   MOB_L001_R1_001.gz MOB_L001_R2_001.gz      
      MOB   2   MOB_L002_R1_001.gz MOB_L002_R2_001.gz 
      ASP   1   ASP_L001_R1_001.gz ASP_L001_R2_001.gz 
      ASP   2   ASP_L002_R1_001.gz MOB_L002_R2_001.gz 
      YIP   1   YIP_L001_R1_001.gz YIP_L001_R2_001.gz
      YIP   2   YIP_L002_R1_001.gz YIP_L002_R2_001.gz
  </code></pre>
  
  <p>Any help/suggestions are appreciated!!</p>