Python nested json to csv

Question

I can't convert this Json to csv. I have been trying with different solutions posted here using panda or other parser but non solved this.

This is a small extract of the big json

{'data': {'items': [{'category': 'cat',
                 'coupon_code': 'cupon 1',
                 'coupon_name': '$829.99/€705.79 ',
                 'coupon_url': 'link3',
                 'end_time': '2017-12-31 00:00:00',
                 'language': 'sp',
                 'start_time': '2017-12-19 00:00:00'},
                {'category': 'LED ',
                 'coupon_code': 'code',
                 'coupon_name': 'text',
                 'coupon_url': 'link',
                 'end_time': '2018-01-31 00:00:00',
                 'language': 'sp',
                 'start_time': '2017-10-07 00:00:00'}],
      'total_pages': 1,
      'total_results': 137},
       'error_no': 0,
       'msg': '',
       'request': 'GET api/ @2017-12-26 04:50:02'}

I'd like to get an output like this with the columns:

category, coupon_code, coupon_name, coupon_url, end_time, language, start_time

I'm running python 3.6 with no restrictions.