Kivy 产品搜索计划

Question

from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.gridlayout import GridLayout
from kivy.uix.textinput import TextInput
from kivy.uix.button import Button
from kivy.uix.screenmanager import ScreenManager, Screen
import json
import re

class Grid(GridLayout):

def __init__(self, **kwargs):
    super(Grid, self).__init__(**kwargs)

    # Columns for the main view
    self.cols = 1


    # Start of the Inside
    self.inside = GridLayout()
    self.inside.rows = 3


    self.inside.add_widget(Label(text = 'Enter the Brand Name for its Products: '))
    self.brand_input = TextInput(multiline = False)
    self.inside.add_widget(self.brand_input)


    # Add the things in inside to the main
    self.add_widget(self.inside)


    self.submit = Button(text = 'Submit', font_size = 20)
    self.submit.bind(on_press = self.pressed)
    self.add_widget(self.submit)


def pressed(self, instance):
    # Pull the text inside the textInput
    brand_name = self.brand_input.text

    with open('mcg_app/brands.json', 'r') as f:
        brands_dict = json.load(f)

    request = brands_dict[brand_name]
    modified_result = re.sub(r',\s(?![^(]*\))', "\n", str(request))

    self.inside.add_widget(Label(text = modified_result))

    # Clear out the fields after submitting
    self.brand_input.text = ''





class Mcg(App):

def build(self):
    return Grid()



if __name__ == '__main__':
    Mcg().run()

你好，这里的程序有一个文本输入框，用户输入一个品牌名称，例如“Dove”，然后他按下提交按钮，按钮连接到pressed()函数。该程序的一切实际上都运行良好，唯一的问题是在我打印输入品牌的产品之后，假设他输入了不同的品牌，在这种情况下，旧的输出仍然存在，所以程序输出的新产品已经存在旧产品。我怎样才能解决这个问题？提前致谢

Answer 1

如果没有 json 数据文件，我无法真正对其进行测试，但请查看以下内容：

from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.gridlayout import GridLayout
from kivy.uix.textinput import TextInput
from kivy.uix.button import Button
import json
import re


class Grid(GridLayout):

    def __init__(self, **kwargs):
        super(Grid, self).__init__(**kwargs)

        # Columns for the main view
        self.cols = 1

        # Start of the Inside
        self.inside = GridLayout()
        self.inside.rows = 3

        self.inside.add_widget(Label(text='Enter the Brand Name for its Products: '))
        self.brand_input = TextInput(multiline=False)
        self.inside.add_widget(self.brand_input)

        # Add the things in inside to the main
        self.add_widget(self.inside)

        self.submit = Button(text='Submit', font_size=20)
        self.submit.bind(on_press=self.pressed)
        self.add_widget(self.submit)

    def pressed(self, instance):
        # Clear out the fields after submitting
        self.brand_input.text = ''
        self.inside.clear_widgets()
        self.inside.add_widget(Label(text='Enter the Brand Name for its Products: '))
        self.inside.add_widget(self.brand_input)

        # Pull the text inside the textInput
        brand_name = self.brand_input.text

        with open('mcg_app/brands.json', 'r') as f:
            brands_dict = json.load(f)

        request = brands_dict[brand_name]
        modified_result = re.sub(r',\s(?![^(]*\))', "\n", str(request))

        self.inside.add_widget(Label(text=modified_result))


class Mcg(App):

    def build(self):
        return Grid()


if __name__ == '__main__':
    Mcg().run()

它会在每次按下按钮时重置self.inside GridLayout...