在计数器附近显示PI小数号

Question

当前是Python的初学者。

我正在尝试基于PI创建一个简单的TKINTER应用程序(3.14( 每当他们按"下一个数字"时，都会增加计数器 1并显示 下一个小数。

# Import the Tkinter functions
from tkinter import *

#####backend function
global counter
counter = 0
pi = '159265358979323846'

def pi_decimal():
    while counter > 0
         pass
def Decimals():
    global counter
    counter +=1
    display_decimal['text'] = counter

# Create a window
application_window = Tk()
# Give the window a title
application_window.title('PI')
# create a button for application window
my_button = Button(application_window,
                   text = 'Next Digit', command = Decimals)
#create a row that shows the number
number_pi = Label(application_window, text = pi)
display_decimal = Label(application_window, text = counter)
#put button into the window
display_decimal.pack()
number_pi.pack()
my_button.pack()

例如，我试图弄清楚如何浏览最多18的小数列表，例如，添加到3.14中。计数器0 = 3.14，计数器1 = 3.141，计数器2 = 3.1415等。

您可以做这样的事情：

您的应用程序主要缺少对Mainloop的电话。

# Import the Tkinter functions
import tkinter as tk

def decimals():
    global counter
    counter += 1
    try:
        text = pi[counter]
    except IndexError:
        counter = 0
        text = ''
    display_decimal['text'] = f"PI decimal value: {text}"
    display_decimal_ndx['text'] = f"PI decimal index: {counter}" 

if __name__ == '__main__':
    # backend function
    counter = 0
    pi = '159265358979323846'
    # Create a window
    application_window = tk.Tk()
    # Give the window a title
    application_window.title('PI')
    # create a button for application window
    my_button = tk.Button(application_window,
                          text='Next Digit', command=decimals)
    # create a row that shows the number
    number_pi = tk.Label(application_window, text = pi)
    display_decimal = tk.Label(application_window, text='')
    display_decimal_ndx = tk.Label(application_window, text=counter)
    # put button into the window
    display_decimal.pack()
    display_decimal_ndx.pack()
    number_pi.pack()
    my_button.pack()
    application_window.mainloop()

注意：

您可能需要考虑使用import tkinter as tk而不是混乱的全局名称空间。
枚举完成后，功能decimals()中的try/except块避免了讨厌的索引错误。
标签显示显示哪个小数，另一个显示其值。
完成后，将枚举重置为第一个小数。

编辑：

您可以执行类似的操作，以添加数字pi的显示，该数字pi更新在按下按钮时显示的小数数：

import tkinter as tk

def decimals():
    global counter
    counter += 1
    try:
        text = pi[counter]
    except IndexError:
        counter = 4
        text = ''
    display_decimal['text'] = f"PI decimal value: {text}"
    display_decimal_ndx['text'] = f"PI decimal index: {counter}"
    number_pi['text'] = pi[:counter+1]

if __name__ == '__main__':
    # backend function
    counter = 4
    pi = '3.14159265358979323846'
    # Create a window
    application_window = tk.Tk()
    # Give the window a title
    application_window.title('PI')
    # create a button for application window
    my_button = tk.Button(application_window,
                          text='Next Digit', command=decimals)
    # create a row that shows the number
    number_pi = tk.Label(application_window, text = pi[:counter+1])
    display_decimal = tk.Label(application_window, text='')
    display_decimal_ndx = tk.Label(application_window, text=counter)
    # put button into the window
    display_decimal.pack()
    display_decimal_ndx.pack()
    number_pi.pack()
    my_button.pack()
    application_window.mainloop()