title: Pandas: How to append new columns to all rows in data frame
body: <p>I have two data frames:</p>
  
  <pre><code>df1 = pd.DataFrame(data={
    'ColumnA': ['A1','A2','A3'],
    'ColumnB' : [ 'B1','B2','B3'],
    'ColumnC' : [ 'C1','C2','C3']
  })
  
  
  df2 = pd.DataFrame(data={
    'id': ['1'],
    'Value1' : [ 'v1'],
    'Value2' : [ 'v2']
  })
  
  
  
    ColumnB ColumnC columnA id
  0      B1      C1      A1  1
  1      B2      C2      A2  1
  2      B3      C3      A3  1
  
  
    Value1 Value2 id
  0     v1     v2  1
  </code></pre>
  
  <p>And looking to get df3 where all rows on df1 will have columns from df2.</p>
  
  <pre><code>  ColumnB ColumnC columnA id Value1 Value2
  0      B1      C1      A1  1     v1     v2
  1      B2      C2      A2  1     v1     v2
  2      B3      C3      A3  1     v1     v2
  </code></pre>
  
  <p>Currently im doing it this way:</p>
  
  <pre><code>id = df2['id'][0]
  df1['id'] = id
  
  df3 = df1.merge(df2,left_on='id',right_on='id',how='left')
  </code></pre>
  
  <p>What is the better way to do it?</p>