def aggregate_customers_sessions(sessions):
    """
    Receives as input what products customers interacted with and returns their final
    aggregation.
    
    Args
    ----
      sessions: list of list of dicts.
          List where each element is a list of dict of type: [{'action': '', 'sku': ''}]
          
    Returns
    -------
      results: list of dicts
          Each resulting dict is aggregated on the sku and action level (repeating
          clauses are filtered out).
    """
    result = []
    for session in sessions:
        for hit in session:
            result.append(hit)
    return [dict(t) for t in {tuple(d.items()) for d in result}]