title: Pandas: join DataFrames on field with different names?
body: <p>According to <a href="http://pandas.pydata.org/pandas-docs/stable/comparison_with_sql.html#left-outer-join" rel="noreferrer">this documentation</a> I can only make a join between fields having the same name.</p>
  
  <p>Do you know if it's possible to join two DataFrames on a field having different names?</p>
  
  <p>The equivalent in SQL would be:</p>
  
  <pre><code>SELECT *
  FROM df1
  LEFT OUTER JOIN df2
    ON df1.id_key = df2.fk_key
  </code></pre>