title: how to remove duplicates in the table generated in sql using python
body: <p>I run two queries in python (that would generate two different data sets but has the same title). I combined them into one data set using python and it looks something like this: (however this actual data set is not showing anywhere, I just use table_a + table_b and combined them into one)</p>
  
  <pre><code>date      symbol    data
  10/9/2018   a       0.1
  10/9/2018   b       0.2
  10/9/2018   c       0.3
  10/9/2018   a       0.1
  10/9/2018   a       0.1
  </code></pre>
  
  <p>If i want to remove the duplicates symbol and produce output like:</p>
  
  <pre><code>date      symbol    data
  10/9/2018   a       0.1
  10/9/2018   b       0.2
  10/9/2018   c       0.3
  </code></pre>
  
  <p>how should I do it?</p>
  
  <p>Thanks!</p>