用于货币兑换计算的python应用程序[关闭]

Question

我的目标是创建一个简单的基于应用程序的计算器——从一种货币转换为另一种货币，但转换率应该从网站自动检索。为此，我决定使用 kivy library.based on the following example： kivy 计算器 我设法改变了一些小部分并得到了以下代码和结果：

这里是.py文件和.kv文件的代码

`import kivy

# base Class of your App inherits from the App class.
# app:always refers to the instance of your application
from kivy.app import App

# this restrict the kivy version i.e
# below this kivy version you cannot
# use the app or software
kivy.require('1.9.0')

# for making multiple buttons to arranging
# them we are using this
from kivy.uix.gridlayout import GridLayout

# for the size of window
from kivy.config import Config

# Setting size to resizable
Config.set('graphics', 'resizable', 1)


## Config.set('graphics', 'width', '400')
## Config.set('graphics', 'height', '400')


# Creating Layout class
class CalcGridLayout(GridLayout):

    # Function called when equals is pressed
    def calculate(self, calculation):
        if calculation:
            try:
                # Solve formula and display it in entry
                # which is pointed at by display
                self.display.text = str(eval(calculation))
            except Exception:
                self.display.text = "Error"


# Creating App class
class CalculatorApp(App):

    def build(self):
        return CalcGridLayout()


# creating object and running it
calcApp = CalculatorApp()
calcApp.run()`

和对应的.kv文件

<CustButton@Button>:
    font_size: 32

# Define id so I can refer to the CalcGridLayout
# class functions
# Display points to the entry widget

``<CalcGridLayout>:
    id: calculator
    display: entry
    rows: 6
    padding: 10
    spacing: 10



    # Where input is displayed
    BoxLayout:
        TextInput:
            id: entry
            font_size: 32
            multiline: False

    # When buttons are pressed update the entry
    BoxLayout:
        spacing: 10
        CustButton:
            text: "7"
            on_press: entry.text += self.text
        CustButton:
            text: "8"
            on_press: entry.text += self.text
        CustButton:
            text: "9"
            on_press: entry.text += self.text
        CustButton:
            text: "$"
            on_press: entry.text =entry.text+'/'+ str(2.54)

    BoxLayout:
        spacing: 10
        CustButton:
            text: "4"
            on_press: entry.text += self.text
        CustButton:
            text: "5"
            on_press: entry.text += self.text
        CustButton:
            text: "6"
            on_press: entry.text += self.text
        CustButton:
            text: "yen"
            on_press: entry.text =entry.text+'*'+ str(54.21)

    BoxLayout:
        spacing: 10
        CustButton:
            text: "1"
            on_press: entry.text += self.text
        CustButton:
            text: "2"
            on_press: entry.text += self.text
        CustButton:
            text: "3"
            on_press: entry.text += self.text
        CustButton:
            text: "euro"
            on_press: entry.text =entry.text+'/'+ str(2.8070)

    # When equals is pressed pass text in the entry
    # to the calculate function
    BoxLayout:
        spacing: 10
        CustButton:
            text: "AC"
            on_press: entry.text = ""
        CustButton:
            text: "0"
            on_press: entry.text += self.text
        CustButton:
            text: "="
            on_press: calculator.calculate(entry.text)
        CustButton:
            text: "GBP"
            on_press: entry.text =entry.text+'/'+ str(3.1790)
    BoxLayout:
        CustButton:
            font_size: 20
            text: "Scientific calculator"
            on_press: entry.text = ""

`

当我运行 .py 文件时，我得到了这个结果：

但问题是，如果我们看一下代码：

  text: "GBP" on_press: entry.text =entry.text+'/'+ str(3.1790)

GBP 是静态的，如果我想使用 beautifull soup 从 web 获取这些数据，如何将结果合并到我们的类中？请给我一个提示

编辑：由于对问题的评论不明确，我不清楚我在问什么，我会重复问题： 看看下面的代码：

 text: "GBP"
            on_press: entry.text =entry.text+'/'+ str(3.1790)

不是直接写汇率，我如何从网站上读取它并包含在 kivy 中，这里有什么不清楚的？寻找例如以下链接： 汇率

你能看到关于英镑的信息吗？如何得到这个并包含在kivy中？我知道我可以通过 beuatifulsoup 得到它，但是如何包含在 kivy 中，现在清楚了吗？