如何在python中读取json对象

i have json file named "panamaleaks50k.json" . I want to get ['text'] field from json file but it shows me following error

JSON对象必须是str、bytes或bytearray，而不是"TextIOWrapper"

this is my code

with open('C:/Users/bilal butt/Desktop/PanamalEakJson.json','r') as lst:
    b = json.loads(lst)
    print(b['text'])

我的json文件外观

[
{
   "fullname": "Mohammad Fayyaz",
   "id": "885800668862263296",
   "likes": "0",
   "replies": "0",
   "retweets": "0",
   "text": "Love of NS has been shown in PanamaLeaks scandal verified by JIT...",
   "timestamp": "2017-07-14T09:58:31",
   "url": "/mohammadfayyaz/status/885800668862263296",
   "user": "mohammadfayyaz"
 },
{
  "fullname": "TeamPakistanPTI \u00ae",
  "id": "885800910357749761",
  "likes": "0",
  "replies": "0",
  "retweets": "0",
  "text": "RT ArsalanISF: #PanamaLeaks is just a start. U won't believe whr...",
  "timestamp": "2017-07-14T09:59:29",
  "url": "/PtiTeampakistan/status/885800910357749761",
  "user": "PtiTeampakistan"
 }
]

how i can read all ['text'] and just single ['text'] field?