title: Combining CSV's with Different Columns using Pandas [with key column]
body: <p>I'm trying to combine two CSV files in Python, each CSV file has unique columns but both CSV files share a common key column.</p>
  
  <p>I've been looking around StackOverflow/Google/Pandas documentation but didn't find exactly what I was looking for. The examples provided on the Pandas documentation pages for merge and concat are different from what I'm trying to achieve so I'm not sure if what I'm asking is possible with Pandas.</p>
  
  <p>I've read in selected columns from both CSV files into separate dataframes, what I would like to do now is combine the two dataframes into a single dataframe based on the key column.</p>
  
  <pre><code>Example
  
  CSV 1:
  Key   Make   Model
  501   Audi   A3
  502   Audi   A4
  503   Audi   A5
  
  CSV 2:
  Key   Engine
  501   2.0T
  502   2.0T
  503   2.0T
  
  Combined Expected Result:
  Key   Make   Model   Engine
  501   Audi   A3      2.0T
  502   Audi   A4      2.0T
  503   Audi   A5      2.0T
  </code></pre>