无法将字符串转换为浮点数：python(Tkinter)中的错误

Question

我编写了一个程序，将一种货币转换为另一种货币(在本例中仅将韩元转换为美元)。然而，当我尝试点击美国单选按钮时，它说"无法将字符串转换为浮动"。那么，问题是什么呢?我试图在没有额外窗口的情况下运行它，它工作得很好，但是当我在新窗口中打开转换器窗口时，它不起作用。问题是什么，我如何使它，所以转换器将工作良好，当你打开它在一个新的窗口?

import tkinter as tk
from tkinter import ttk
from tkinter.messagebox import showerror
from tkinter import *
root = tk.Tk()
root.geometry('5000x5000')
def openconverter():    
root = tk.Tk()
root.title('Change Converter')
root.geometry('400x210')
def won_to_dollar(f):
US = 0.00079
return f*US
frame = ttk.Frame(root)
options = {'padx': 5, 'pady': 5}
won = tk.StringVar()
won_entry = ttk.Entry(frame, textvariable=won)
won_entry.grid(column=1, row=0, **options)
def convert_button_clicked(won_to_dollar):
try:
f = float(won.get())
c = won_to_dollar(f)
result = f'{f} won = {c:.2f}'
result_label.config(text=result)
except ValueError as error:
showerror(title='Error', message=error)
result_label = ttk.Label(frame)
result_label.grid(row=1, columnspan=3, **options)
frame.grid(padx=10, pady=10)
r = IntVar()
Radiobutton(root, text="US", variable = r, value = 1, command = lambda : convert_button_clicked(won_to_dollar)).place(x = 220, y = 20)
myLabel = Label(root, text = r.get())
myLabel.grid
root.mainloop()

Converted = Button(root, text="converter",font = ("Helvetica", 15), width=50, height=50, compound="c", activeforeground = "green", command = lambda: openconverter())
Converted.place(x=10, y=185) 
root.mainloop()

Answer 1

试试这个，点击转换并输入值并选择US。

from tkinter import ttk
from tkinter.messagebox import showerror
from tkinter import *
root = Tk()

root.title('Change Converter')
root.geometry('400x810')

def openconverter():     
def won_to_dollar(f):
US = 0.00079
return f*US
frame = Frame(root)
options = {'padx': 5, 'pady': 5}
won = StringVar()
won_entry = Entry(frame, textvariable=won)
won_entry.grid(column=1, row=0, **options)
def convert_button_clicked(won_to_dollar):
try:
f = won.get()
c = won_to_dollar(float(f))
result = f'{f} won = {c}'
result_label.config(text=result)
except ValueError as error:
showerror(title='Error', message=error)

result_label = Label(frame)
result_label.grid(row=1, columnspan=3, **options)
frame.grid(padx=10, pady=10)
r = IntVar()
Radiobutton(root, text="US", variable = r,
value = 1,
command = lambda : convert_button_clicked(won_to_dollar)).place(x = 220, y = 20)
myLabel = Label(root, text = r.get())
myLabel.grid


Converted = Button(root, text="converter",
font = ("Helvetica", 15), width=50, height=50, compound="c",
activeforeground = "green", command = lambda: openconverter())
Converted.place(x=10, y=5) 
root.mainloop()