title: Python - Find duplicates in a list of dictionaries and group them
body: <p>i'm not a programmer and also new to python, i have a list of dicts coming from a json file:</p>
  
  <pre><code># JSON file (film.json)
  [{"year": ["1999"], "director": ["Wachowski"], "film": ["The Matrix"], "price": ["19,00"]},
  {"year": ["1994"], "director": ["Tarantino"], "film": ["Pulp Fiction"], "price": ["20,00"]},
  {"year": ["2003"], "director": ["Tarantino"], "film": ["Kill Bill vol.1"], "price": ["10,00"]},
  {"year": ["2003"], "director": ["Wachowski"], "film": ["The Matrix Reloaded"], "price": ["9,99"]},
  {"year": ["1994"], "director": ["Tarantino"], "film": ["Pulp Fyction"], "price": ["15,00"]},
  {"year": ["1994"], "director": ["E. de Souza"], "film": ["Street Fighter"], "price": ["2,00"]},
  {"year": ["1999"], "director": ["Wachowski"], "film": ["The Matrix"], "price": ["20,00"]},
  {"year": ["1982"], "director": ["Ridley Scott"], "film": ["Blade Runner"], "price": ["19,99"]}]
  </code></pre>
  
  <p>i can import json file with:</p>
  
  <pre><code>import json
  json_file = open('film.json')
  f = json.load(json_file)
  </code></pre>
  
  <p>but after that i'm not able to find occurrences in <code>f</code> and separate them in groups by film title.
  This is what i'm looking for to achieve:</p>
  
  <pre><code>## result grouped by 'film'
  #group 1
  {"year": ["1999"], "director": ["Wachowski"], "film": ["The Matrix"], "price": ["19,00"]}
  {"year": ["1999"], "director": ["Wachowski"], "film": ["The Matrix"], "price": ["20,00"]}
  #group 2
  {"year": ["1994"], "director": ["Tarantino"], "film": ["Pulp Fiction"], "price": ["20,00"]}
  {"year": ["1994"], "director": ["Tarantino"], "film": ["Pulp Fyction"], "price": ["15,00"]}
  #group X
   ...
  </code></pre>
  
  <p>Or better:</p>
  
  <pre><code>new_dict = { 'group1':[[],[],...] , 'group2':[[],[],...] , 'groupX':[...] }
  </code></pre>
  
  <p>At the moment i'm testing with nested <code>for</code> but without luck..</p>
  
  <p>Thank you.</p>
  
  <p>note: "pulp fyction" is a wanted mistake for future implementation with fuzzy string matching, for now i need only a 'duplicates grouper'</p>
  
  <p>note2: with python 2.x</p>