title: Creating a dictionary in python by combining two .csv files
body: <p>I am trying to create a dictionary in python by combining data from two .csv files, by matching the first column of the two files.  This is what I have so far </p>
  
  <pre><code>import csv
  
  with open('a.csv', 'r') as my_file1 :
      rows1 = list(csv.reader(my_file1))
  with open('aa.csv', 'r') as my_file2 :
      rows2 = list(csv.reader(my_file2))
  max_length = min(len(rows1), len(rows2))
  
  for i in range(10):
      new_dict = {}
      if (rows1[i][0]== rows2[i][0]):
          temp = {(rows1[i][0], (rows1[i][5], rows1[i][6],  rows2[i][5],  rows2[i][6] )) }
          new_dict.update(temp)
  print(new_dict)
  </code></pre>
  
  <p>The output that I get is the last data entry in arrays. It does not seem to append all the values.  This is what the output looks like </p>
  
  <pre><code>{'2016-09-12': ('1835400', '45.75', '21681500', '9.78')}
  </code></pre>
  
  <p>instead of the complete list with keys and values.  How do I go about correcting this?  Thanks!  </p>