【发布时间】:2016-04-21 18:49:02
【问题描述】:
我正在使用 python 和 kivy 制作一个应用程序,允许用户为其葡萄糖读数创建一个新条目。现在它保存到 json 文件中,但另一个新条目删除了以前的数据。如何使每个条目分别保存,以便我可以访问用户历史记录的信息?
.py 文件
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.popup import Popup
from kivy.uix.button import Button
from kivy.graphics import Color, Rectangle
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.image import AsyncImage
from kivy.uix.label import Label
from kivy.properties import StringProperty, ListProperty
from kivy.uix.behaviors import ButtonBehavior
from kivy.uix.textinput import TextInput
from kivy.network.urlrequest import UrlRequest
from kivy.storage.jsonstore import JsonStore
from os.path import join
from os.path import exists
from kivy.compat import iteritems
from kivy.storage import AbstractStore
from json import loads, dump
from kivy.config import Config
import os
import errno
class Phone(FloatLayout):
def __init__(self, **kwargs):
# make sure we aren't overriding any important functionality
super(Phone, self).__init__(**kwargs)
with self.canvas.before:
Color(0, 1, 0, 1) # green; colors range from 0-1 instead of 0-255
self.rect = Rectangle(size=self.size, pos=self.pos)
self.bind(size=self._update_rect, pos=self._update_rect)
if not os.path.exists('hello.json'):
with open('hello.json', 'wt') as inFile:
inFile.write("")
else:
with open('hello.json') as inFile:
try:
data = Phone.load(self)
except KeyError:
data = []
def _update_rect(self, instance, value):
self.rect.pos = instance.pos
self.rect.size = instance.size
def product(self, instance):
self.result.text = str(float(self.w.text) * 703/ (float(self.h.text) * float(self.h.text)))
def save(self):
store = JsonStore('hello.json')
name = self.n.text
gender = self.g.text
dtype = self.t.text
height = self.h.text
weight = self.w.text
bmi = self.result.text
medications = self.m.text
insulin = self.ti.text
store.put('profile', name=name, gender=gender, dtype=dtype, height=height, weight=weight, bmi=bmi, medications=medications, insulin=insulin)
def save_entry(self):
time = self.gt.text
glucose = self.gr.text
carbs = self.c.text
medications_taken = self.mt.text
store.put('entry', time=time, glucose=glucose, carbs=carbs, medications_taken=medications_taken)
def load(self):
store = JsonStore('hello.json')
profile = store.get('profile')
self.n.text = profile['name']
self.g.text = profile['gender']
self.t.text = profile['dtype']
self.h.text = profile['height']
self.w.text = profile['weight']
self.result.text = profile['bmi']
self.m.text = profile['medications']
self.ti.text = profile['insulin']
presentation = Builder.load_file("main.kv")
class PhoneApp(App):
def build(self):
store = JsonStore('hello.json')
return Phone()
if __name__ == '__main__':
PhoneApp().run()
【问题讨论】:
-
加载 json,解码为本机结构,对该结构进行必要的更改,然后重新编码为 json 并保存新副本。
-
@MarcB 如何解码为原生结构?
标签: android python json save kivy