CSVEmitter.py

import csv, StringIO

class CSVEmitter(Emitter):
    def get_keys(self, input_dict):
        keys = []
        for item in input_dict.items():
            if isinstance(item[1], dict):
                keys.extend(self.get_keys(item[1]))
            else:
                keys.append(item[0])
        return keys
    
    def get_values(self, input_dict):
        for item in input_dict.items():
            if isinstance(item[1], dict):
                input_dict.update(self.get_values(input_dict.pop(item[0])))
            else:
                input_dict[item[0]] = smart_str(item[1])
        return input_dict
    
    def render(self, request):
        response = StringIO.StringIO()
        content = self.construct()
        keys = self.get_keys(content[0])
        
        writer = csv.DictWriter(response, keys, dialect='excel')
        headers = dict((n,n) for n in keys)
        writer.writerow(headers)
        for row in content:
            writer.writerow(self.get_values(row))
        
        return response
        
Emitter.register('csv', CSVEmitter, 'application/csv; charset=utf-8')