title: file to dictionary:value is a dictionary where the key is repeated
body: <p>I open a file which contains this:</p>
  
  <pre><code>TransactionNo   Date        CustomerId      PurchasePairs
  -------------   ----        ----------      -------------
  1               09-04-2014  barakobama      potatoes:2.67,sugar:1.98,cereal:5.99,crisps:1.09
  2               11-04-2014  barakobama      parsley:0.76,cereal:3.22
  3               11-04-2014  vladimirputin   bread:0.66,milk:2.87,parsley:1.33
  </code></pre>
  
  <p>and i want output dictionary like this:</p>
  
  <pre><code>{'milk': {'vladimirputin': 2.87}, 'cereal': {'barakobama': 9.21},
  'bread': {'vladimirputin': 0.66}, 'potatoes': {'barakobama': 2.67}, 
  'sugar': {'barakobama': 1.98}, 'parsley': {'vladimirputin': 1.33,
  </code></pre>
  
  <p>I have done this:</p>
  
  <pre><code> C={}
  file=open(fileNameStr,'r')
  
  
  for line in file:
      if line[0].isdigit():
          fields = line.split()
  </code></pre>