title: How to use subscripts in an Optional Array of Dictionary
body: <p>I am attempting to read a csv file on linux using the CSwiftV library, however the returned type that interests me the most is an optional array of dictionaries. I have been struggling to understand how to use subscripting to access the contents of the Array. Using the library most basic example (if you have marathon installed, just copy on a file and <code>marathon run</code>):</p>
  
  <pre><code>import CSwiftV // marathon: https://github.com/Daniel1of1/CSwiftV.git
  
  let inputString = "Year,Make,Model,Description,Price\r\n1997,Ford,E350,descrition,3000.00\r\n1999,Chevy,Venture,another description,4900.00\r\n"
  
  let csv = CSwiftV(with: inputString)
  
  let rows = csv.rows // [
                      //  ["1997","Ford","E350","descrition","3000.00"],
                      //  ["1999","Chevy","Venture","another description","4900.00"]
                      // ]
  
  let headers = csv.headers // ["Year","Make","Model","Description","Price"]
  
  let keyedRows = csv.keyedRows // [
                                //  ["Year":"1997","Make":"Ford","Model":"E350","Description":"descrition","Price":"3000.00"],
                                //  ["Year":"1999","Make":"Chevy","Model":"Venture","Description":"another, description","Price":"4900.00"]
                                // ]
  
  print(csv.rows)
  print(csv.headers)
  print(csv.keyedRows)
  </code></pre>
  
  <p>So far so good, but now when I try <code>print(csv.keyedRows[0][0])</code> or <code>print(csv.keyedRows[[0]])</code> I get something like:</p>
  
  <pre><code>   - 24:16: value of optional type '[[String : String]]?' must be unwrapped to refer to member 'subscript' of wrapped base type '[[String : String]]'
  </code></pre>
  
  <ul>
  <li>How can I access the dictionary data in this case (I am thinking on something similar to <code>csv.keyedRows[0]["Year"]</code>) ?</li>
  </ul>