import json
body={'discountPrice':{'1':'5.4847','59':'5.1938','100':'4.9030'}}

 #将dict类型的数据转换成str
jsDumps=json.dumps(body)
jsLoads = json.loads(jsDumps)
if ('discountPrice' in jsLoads) :
    print('存在')
else:
    print('不存在')


#循环获取key和value
for r in jsLoads['discountPrice']:
    print(f'qty:{r} price{jsLoads["discountPrice"][r]}')