import os
import csv
import json

BASE_DIR = 'path/to/dataset/dir'
csv_set = os.path.join(BASE_DIR, 'file.csv')
json_set = os.path.join(BASE_DIR, 'file.json')

with open(csv_set, 'r') as csv_data:
    reader = csv.DictReader(csv_data, fields)

    with open(json_set, 'w') as jsonfile:
        for row in reader:
            json.dump(row, jsonfile)
            jsonfile.write('\n')