python 使用post时候转为json格式

可以使用json.dumps()
目标json

json_data = {
    'changeType': '1',
    'categoryId': '16',
    'indexTrans': '[{"tradeIndex":"1212","num":1},{"tradeIndex":"2323","num":1},{"tradeIndex":"4545","num":1}]',
}

动态改变

import json

a = [1212,2323,4545]

c = {
    'changeType': '1',
    'categoryId': '16',
    'indexTrans': json.dumps([{"tradeIndex":"%s" %(i),"num":index+1} for index, i in enumerate(a)]),

}

print(c)