title: Write a 2d array to a csv file with delimiter
body: <p>As the title says, I want to write a 2D array to a csv file with delimiter ',' using python. My array looks like this (ndarray):</p>
  
  <pre><code>a= [[1,2,3,4],[5,6,7,8]]
  </code></pre>
  
  <p>and I want the output to look like:  </p>
  
  <pre><code>1,2,3,4
  5,6,7,8
  
  with open('./data/positive.csv','wb') as myfile:
    wr = csv.writer(myfile) #, quoting=csv.QUOTE_ALL)
    wr.writerow(a)
  </code></pre>
  
  <p>How do I accomplish this?</p>
  
  <p>I already have tried the solution but it doesn't work since I misplaced an 's' in my 'row' and it makes my array write to a single row instead of multiple rows.</p>