辨别 Python 中 load 和 loads 的小技巧

load 和 loads 都是实现“反序列化”，load 通过 json.load(open('*.json')) 这样的格式，从文件句柄中打开文件，加载到Python的变量中，并以字典的格式转换。而 loads 必须对于 Python内存中的序列化对象转换成字符串。

load 和 loads 都是实现 “反序列化”，区别在于（以Python为例）：

• loads 针对 内存对象，即将 Python内置数据序列化为字串。如使用json.dumps序列化的对象d_json=json.dumps({'a':1, 'b':2})，在这里 d_json 是一个字串'{"b": 2, "a": 1}'，d=json.loads(d_json)  #{ b": 2, "a": 1}，使用load重新反序列化为dict
• load 针对 ​​文件句柄​​。如本地有一个 json 文件 a.json 则可以 d=json.load(open('a.json'))，相应的，dump 就是将内置类型序列化为 json 对象后写入文件

测试 ( 使用 loads )

list_1 = '[1,2,3,4]'
dict_1 = '{"k1":"v1"}'
print(type(list_1)) # <class 'str'>
print(type(dict_1)) # <class 'str'>


ret = json.loads(list_1)
print(ret, type(ret))

ret = json.loads(dict_1)
print(ret, type(ret))

# 输出
# [1, 2, 3, 4] <class 'list'>
# {'k1': 'v1'} <class 'dict'>

测试( 使用 load )：

# -*- coding: utf-8 -*-
# @Time    :
# @Author  :
# @Email   :
# @File    : parse_cinema_info.py
# @Software: PyCharm


import json


def parse_cinema_info():
    cinema_info_dict = json.load(open('f:/bj_cinema_all_info.json', "rb"))
    all_cinemas = cinema_info_dict['cinemas']
    cinemas_list = list()
    for cinema in all_cinemas:
        d = dict(
            cinema_id=cinema['id'],
            cinema_name=cinema['nm'],
            city='北京',
            address=cinema['addr'],
            telephone=None
        )
        cinemas_list.append(d)
    with open('f:/bj_cinema.json', 'w') as f:
        json.dump(cinemas_list,f, ensure_ascii=False, indent=4)
    pass


if __name__ == '__main__':
    parse_cinema_info()
    pass

使用 dump：

# -*- coding: utf-8 -*-
# @Time    : 
# @Author  : 
# @Email   : 
# @File    : parse_cinema_hall_info.py
# @Software: PyCharm

import re
import json


def parse_file():
    cinema_hall_info = dict()
    with open('f:/pipelines.log', 'rb') as f:
        all_lines = f.readlines()
    for line in all_lines:
        line_str = line.decode('utf-8')
        base_time_info = re.findall("\('.*?'\)", line_str)
        if base_time_info:
            hall_info_list = list()
            for base_time in base_time_info:
                t = tuple(eval（base_time))
                cinema_id, hall_info = t[1], t[8]
                if hall_info not in hall_info_list:
                    hall_info_list.append(hall_info)
                cinema_hall_info[cinema_id] = hall_info_list
    else:
        # print(json.dumps(cinema_hall_info, ensure_ascii=False))
        hall_info_list = list()
        for cinema in cinema_hall_info:
            # print('cinema_id : {0}    hall_info : {1}'.format(cinema, cinema_hall_info[cinema]))
            d = dict(
                cinema_id=cinema,
                hall_info=cinema_hall_info[cinema],
                seat_count=None
            )
            hall_info_list.append(d)
        else:
            with open('f:/bj_cinema_hall.json', 'w') as f:
                json.dump(hall_info_list, f, ensure_ascii=False, indent=4)


if __name__ == '__main__':
    parse_file()
    pass

一个测试 json 文件 （bj_cinema_all_info.json）：

{
  "cinemas": [
    {
      "id": 264,
      "mark": 0,
      "nm": "万达国际影城(CBD店)",
      "sellPrice": "48.5",
      "addr": "朝阳区建国路93号万达广场B座3层",
      "distance": "600m",
      "tag": {
        "allowRefund": 0,
        "buyout": 0,
        "cityCardTag": 0,
        "deal": 0,
        "endorse": 0,
        "hallType": [
          "IMAX厅",
          "RealD 6FL厅",
          "4DX厅"
        ],
        "hallTypeVOList": [
          {
            "name": "IMAX厅",
            "url": ""
          },
          {
            "name": "RealD 6FL厅",
            "url": ""
          },
          {
            "name": "4DX厅",
            "url": ""
          }
        ],
        "sell": 1,
        "snack": 1,
        "vipTag": "折扣卡"
      },
      "promotion": {
        
      }
    },
    {
      "id": 23,
      "mark": 0,
      "nm": "百丽宫影城(国贸店)",
      "sellPrice": "29",
      "addr": "朝阳区建国门外大街1号国贸商城北区B1层B120",
      "distance": "1km",
      "tag": {
        "allowRefund": 0,
        "buyout": 0,
        "cityCardTag": 0,
        "deal": 0,
        "endorse": 0,
        "hallType": [
          "RealD厅"
        ],
        "hallTypeVOList": [
          {
            "name": "RealD厅",
            "url": ""
          }
        ],
        "sell": 1,
        "snack": 1
      },
      "promotion": {
        
      }
    }
  ],
  "ct_pois": [
    {
      "ct_poi": "936879945111165696_a15272_c223",
      "poiid": 99082156
    },
    {
      "ct_poi": "936879945111165696_a2378_c224",
      "poiid": 1541434
    },
    {
      "ct_poi": "936879945111165696_a15748_c225",
      "poiid": 94728699
    }
  ],
  "paging": {
    "hasMore": false,
    "limit": 10000,
    "offset": 0,
    "total": 226
  }
}