（python）如何在tkinter环境中将函数转换为模块

Question

我尝试将功能转换为TKINTER中的模块。但是，它失败了。

原始版本：在主代码中嵌入函数（sl_adder）

，我使用.get（）函数

from tkinter import *
import tkinter.ttk as ttk

def sl_adder():
    aa = float(xxx.get())
    bb = float(yyy.get())
    cc = aa + bb
    mylabel = ttk.Label(root, text = cc).grid(column=1, row=4, padx=10, pady=15, sticky=N)

root = Tk()
root.title('Denny')
root.geometry("800x900")

xxx = StringVar()
yyy = StringVar()



ttk.Label(root,text = "Adding System", font=('Arial', 25)).grid(column=0, row=0, ipadx=5, pady=5, sticky=W+N)  
ttk.Label(root,text = "Input Two Numbers", font=('Arial', 10)).grid(column=0, row=1, ipadx=5, pady=20, sticky=W+N)   
ttk.Label(root,text = "1st number: ", font=('Arial', 10)).grid(column=0, row=2, ipadx=5, pady=15, sticky=W+N)   
ttk.Label(root,text = "2nd number: ", font=('Arial', 10)).grid(column=0, row=3, ipadx=5, pady=15, sticky=W+N)  

ttk.Entry(root, textvariable=xxx, width=20).grid(column=1, row=2, padx=10, pady=15, sticky=N) 
ttk.Entry(root, textvariable=yyy, width=20).grid(column=1, row=3, padx=10, pady=15, sticky=N)

resultButton = ttk.Button(root, text = 'Calculate', command = sl_adder)
resultButton.grid(column=3, row=2, pady=15, sticky=W)

close_window = ttk.Button(root, text="Destroy", command = root.destroy)
close_window.grid(column=3, row=3, pady=15, sticky=W)

第二版：将函数转换为模块（sl_adder）

from tkinter import *
import tkinter.ttk as ttk
from sl_adder import sl_adder   # <-------------------------

root = Tk()
root.title('Denny')
root.geometry("800x900")

xxx = StringVar()
yyy = StringVar()



ttk.Label(root,text = "Adding System", font=('Arial', 25)).grid(column=0, row=0, ipadx=5, pady=5, sticky=W+N)  
ttk.Label(root,text = "Input Two Numbers", font=('Arial', 10)).grid(column=0, row=1, ipadx=5, pady=20, sticky=W+N)   
ttk.Label(root,text = "1st number: ", font=('Arial', 10)).grid(column=0, row=2, ipadx=5, pady=15, sticky=W+N)   
ttk.Label(root,text = "2nd number: ", font=('Arial', 10)).grid(column=0, row=3, ipadx=5, pady=15, sticky=W+N)   

ttk.Entry(root, textvariable=xxx, width=20).grid(column=1, row=2, padx=10, pady=15, sticky=N) 
ttk.Entry(root, textvariable=yyy, width=20).grid(column=1, row=3, padx=10, pady=15, sticky=N)

resultButton = ttk.Button(root, text = 'Calculate', command = sl_adder)
resultButton.grid(column=3, row=2, pady=15, sticky=W)

close_window = ttk.Button(root, text="Destroy", command = root.destroy)
close_window.grid(column=3, row=3, pady=15, sticky=W)

模块sl_adder：

def sl_adder():
    aa = float(xxx.get())
    bb = float(yyy.get())
    cc = aa + bb
    mylabel = ttk.Label(root, text = cc).grid(column=1, row=4, padx=10, pady=15, sticky=N)

当我运行它时，它显示了：

NameError: name 'xxx' is not defined

如何修复它？我仅删除功能并产生一个模块。

=============================================== ==========

现在我将其修复为以后的

from tkinter import *
import tkinter.ttk as ttk
from sl_adder import sl_adder

root = Tk()
root.title('Denny')
root.geometry("800x900")

xxx = StringVar()
yyy = StringVar()



ttk.Label(root,text = "Adding System", font=('Arial', 25)).grid(column=0, row=0, ipadx=5, pady=5, sticky=W+N)  
ttk.Label(root,text = "Input Two Numbers", font=('Arial', 10)).grid(column=0, row=1, ipadx=5, pady=20, sticky=W+N)   
ttk.Label(root,text = "1st number: ", font=('Arial', 10)).grid(column=0, row=2, ipadx=5, pady=15, sticky=W+N)   
ttk.Label(root,text = "2nd number: ", font=('Arial', 10)).grid(column=0, row=3, ipadx=5, pady=15, sticky=W+N)   

ttk.Entry(root, textvariable=xxx, width=20).grid(column=1, row=2, padx=10, pady=15, sticky=N) 
ttk.Entry(root, textvariable=yyy, width=20).grid(column=1, row=3, padx=10, pady=15, sticky=N)

aa = float(xxx.get())    # <=====================
bb = float(yyy.get())    # <=====================

resultButton = ttk.Button(root, text = 'Calculate', command = sl_adder(aa,bb))
resultButton.grid(column=3, row=2, pady=15, sticky=W)

close_window = ttk.Button(root, text="Destroy", command = root.destroy)
close_window.grid(column=3, row=3, pady=15, sticky=W)




root.mainloop()

模块

def sl_adder(aa,bb):
    cc = aa + bb
    mylabel = ttk.Label(root, text = cc).grid(column=1, row=4, padx=10, pady=15, sticky=N)

，但是，另一个错误弹出了

aa = float(xxx.get())
ValueError: could not convert string to float: ''

如何修复它？

Answer 1

由于主应用程序和模块在不同的工作区中，因此您无法直接在模块内的主应用程序中访问全局变量。但是，您可以通过函数参数传递它们。

同样，最好在主应用程序而不是内部模块函数中创建结果标签。主应用程序可以从模块函数中获取结果并更新结果文本。

主应用程序：

from tkinter import *
import tkinter.ttk as ttk
from sl_adder import sl_adder

root = Tk()
root.title('Denny')
root.geometry("800x900")

xxx = StringVar()
yyy = StringVar()

ttk.Label(root,text = "Adding System", font=('Arial', 25)).grid(column=0, row=0, ipadx=5, pady=5, sticky=W+N)
ttk.Label(root,text = "Input Two Numbers", font=('Arial', 10)).grid(column=0, row=1, ipadx=5, pady=20, sticky=W+N)
ttk.Label(root,text = "1st number: ", font=('Arial', 10)).grid(column=0, row=2, ipadx=5, pady=15, sticky=W+N)
ttk.Label(root,text = "2nd number: ", font=('Arial', 10)).grid(column=0, row=3, ipadx=5, pady=15, sticky=W+N)

ttk.Entry(root, textvariable=xxx, width=20).grid(column=1, row=2, padx=10, pady=15, sticky=N)
ttk.Entry(root, textvariable=yyy, width=20).grid(column=1, row=3, padx=10, pady=15, sticky=N)

resultButton = ttk.Button(root, text = 'Calculate',
                          # update result label with the returned result
                          command = lambda: mylabel.config(text=sl_adder(xxx.get(), yyy.get())))
resultButton.grid(column=3, row=2, pady=15, sticky=W)

close_window = ttk.Button(root, text="Destroy", command = root.destroy)
close_window.grid(column=3, row=3, pady=15, sticky=W)

# create the label for showing the result
mylabel = ttk.Label(root)
mylabel.grid(column=1, row=4, padx=10, pady=15, sticky=N)

root.mainloop()

模块sl_adder：

def sl_adder(aa, bb):
    # return the result to caller
    return float(aa) + float(bb)