title: How to only use the first match when merging Pandas Dataframes?
body: <p>I have two dataframes: 'data' and 'working'. I am trying to merge data into working on the ID to get the Name into working</p>
  
  <pre><code>Data:
  ID  Name
  a1  a1_Name
  a1  a1_Name1
  
  Working:
  ID  SomeValues 
  a1  123
  a1  456
  </code></pre>
  
  <p>I want the end result to match only on the first found ID each time, but as of now when I do something like </p>
  
  <pre><code>working = pd.merge(working, data, left_on="ID", right_on="ID", sort=False)
  </code></pre>
  
  <p>I get this:</p>
  
  <pre><code>Working:
  ID  SomeValues Name 
  a1  123        a1_Name
  a1  456        a1_Name1
  </code></pre>
  
  <p>and it just alternates between 'a1_Name' and 'a1_Name1'.</p>
  
  <p>I would like it to output:</p>
  
  <pre><code>Working:
  ID  SomeValues Name 
  a1  123        a1_Name
  a1  456        a1_Name
  </code></pre>