[Python]jsonモジュール

test0.py

#-*- coding: utf-8 -*-
import json

#######################################################################
# Main function
#######################################################################
if __name__ == '__main__':
# jsonファイル（辞書型）の読み込み
print('=== read test0_dict_read.txt ===')
f = open('test0_dict_read.txt', 'r')
json_dict = json.load(f)
f.close()

print(json_dict)
print(json_dict['book1'])
print(json_dict['book1']["title"])
print(json.dumps(json_dict, indent=4))

# 辞書型をjsonファイルへ書き出し
print('=== write test0_dict_write.txt ===')
json_dict = {}
data = {}
data['name'] = 'tokyo'
data['temperature_high'] = 37.7
data['temperature_low'] = -2.6
json_dict["prefecture_1"] = data

print(json.dumps(json_dict, indent=4))

f = open('test0_dict_write.txt', 'w')
json.dump(json_dict, f)
f.close()

# jsonファイル（配列型）の読み込み
print('=== read test0_list_read.txt ===')
f = open('test0_list_read.txt', 'r')
json_list = json.load(f)
f.close()

print(json_list)
print(json_list[0])
print(json_list[0]['title'])
print(json.dumps(json_list, indent=4))

# 配列型をjsonファイルへ書き出し
print('=== write test0_list_write.txt ===')
json_list = []
data = {}
data['name'] = 'tokyo'
data['temperature_high'] = 37.7
data['temperature_low'] = -2.6
json_list.append(data)

data = {}
data['name'] = 'naha'
data['temperature_high'] = 33.9
data['temperature_low'] = 6.1
json_list.append(data)

print(json.dumps(json_list, indent=4))

f = open('test0_list_write.txt', 'w')
json.dump(json_list, f)
f.close()

test0_dict_read.txt

{
"book1":{
"title": "Python Beginners",
"year": 2005 ,
"page": 399
},
"book2":{
"title": "Python Developers",
"year": 2006 ,
"page": 650
}
}

test0_list_read.txt

[
{
"title": "Python Beginners",
"year": 2005 ,
"page": 399
},
{
"title": "Python Developers",
"year": 2006 ,
"page": 650
}
]

実行結果 コンソール

$ python test0.py
=== read test0_dict_read.txt ===
{u'book1': {u'year': 2005, u'page': 399, u'title': u'Python Beginners'}, u'book2': {u'year': 2006, u'page': 650, u'title': u'Python Developers'}}
{u'year': 2005, u'page': 399, u'title': u'Python Beginners'}
Python Beginners
{
  "book1": {
  "year": 2005,
  "page": 399,
  "title": "Python Beginners"
  },
  "book2": {
  "year": 2006,
  "page": 650,
  "title": "Python Developers"
  }
}
=== write test0_dict_write.txt ===
{
  "prefecture_1": {
  "temperature_high": 37.7,
  "temperature_low": -2.6,
  "name": "tokyo"
  }
}
=== read test0_list_read.txt ===
[{u'year': 2005, u'page': 399, u'title': u'Python Beginners'}, {u'year': 2006, u'page': 650, u'title': u'Python Developers'}]
{u'year': 2005, u'page': 399, u'title': u'Python Beginners'}
Python Beginners
[
  {
  "year": 2005,
  "page": 399,
  "title": "Python Beginners"
  },
  {
  "year": 2006,
  "page": 650,
  "title": "Python Developers"
  }
]
=== write test0_list_write.txt ===
[
  {
  "temperature_high": 37.7,
  "temperature_low": -2.6,
  "name": "tokyo"
  },
  {
  "temperature_high": 33.9,
  "temperature_low": 6.1,
  "name": "naha"
  }
]

test0_dict_write.txt

{"prefecture_1": {"temperature_high": 37.7, "temperature_low": -2.6, "name": "tokyo"}}

test0_list_write.txt

[{"temperature_high": 37.7, "temperature_low": -2.6, "name": "tokyo"}, {"temperature_high": 33.9, "temperature_low": 6.1, "name": "naha"}]