python - 执行 GUI onclick 命令时，将变量值从一个模块返回到另一个模块时出现问题

Question

我正在编写一个小型词典程序，用户可以在其中打开另一个窗口来添加新单词和定义，以便可以将其添加到主词典中并稍后进行搜索。

我的问题是，虽然用户可以打开一个新窗口来添加单词及其定义，但单击提交按钮时，主词典不会更新。相反，它会抛出一个错误，UnboundLocalError:赋值前引用了局部变量“word”。

我似乎在将新单词/定义变量值传递回主程序时遇到问题。

主程序代码(文件名:Libraryv2.py)

from tkinter import *
import libraryentry



def click():
    entered_text = entry.get() #collect text from text entry box
    output.delete(0.0,END) #clears text box - start clearing from 0.0 (from line 0) to END (after last character)
    try:
        definition = my_glossary[entered_text] #this takes the entered text and uses it as a key for the dictionary, the value found is assigned to definition
    except:
        definition = "No word found in dictionary, try again!"
    output.insert(END, definition) #this inserts the contents of variable 'definition' at the beginning (END) - because it was cleared before, END is the at the start

def clickentry():
    word = libraryentry.main(word)
    definition= libraryentry.main(definition)
    my_glossary[word] = definition

window = Tk()

window.title("My Little Dictionary")

#Create the Label
Label(window, text="Enter the word you want defining:").grid(row=0, column=0, sticky=W)

#create entry box
entry=Entry(window, width=20, bg="light green")
entry.grid(row=1, column=0, sticky=W)

#create submit button
Button(window, text="Submit", width=5, command=click).grid(row=2, column=0, sticky=W)

#create second label
Label(window, text="\nDefinition").grid(row=3, column=0, sticky=W)

#create text box
output=Text(window, width=75, height=6, wrap=WORD, background="light green")
output.grid(row=4, column=0, sticky=W)

#create submit button to open enter new definition window
Button(window, text="Enter a New Definition", width=20, command=clickentry).grid(row=5, column=0, sticky=W)


#Create the Dictionary
my_glossary =   {
                "Algorithm": "Step by step instructions to perform a task",
                "Python": "High-Level Programming language used to write light weight programs",
                "Flow-Chart": "A way to present an algorthim graphically"
                }

window.mainloop()

编辑窗口模块(文件名libraryentry.py):

from tkinter import *

def click2():
    word = entry1.get() #collect text from text entry box
    definition = entry2.get() #collect text from text entry box
    return (word,definition)

def main():
    window = Tk()

    window.title("Library entry")

    #Create the Label
    Label(window, text="Enter the word you want to add:").grid(row=0, column=0, sticky=W)

    #create entry box
    entry1=Entry(window, width=20, bg="light green")
    entry1.grid(row=1, column=0, sticky=W)

    #create second label
    Label(window, text="\nDefinition").grid(row=2, column=0, sticky=W)

    #create entry box
    entry2=Entry(window, width=50, bg="light green")
    entry2.grid(row=3, column=0, sticky=W)

    #create submit button
    Button(window, text="Submit", width=5, command=click2).grid(row=4, column=0, sticky=W)

    return (word, definition)

    window.mainloop()

任何解决此问题的帮助都将不胜感激。为什么我的新单词/定义没有正确传递回主程序？

非常感谢

Answer 1

word = libraryentry.main(word)

执行libraryentry.main(word)没有意义，因为word还不存在，而main也不存在无论如何都不接受任何参数。

word = libraryentry.main()

现在您将在 libraryentry 中收到 NameError: name 'word' is not Defined 因为您正在返回 (word,definition)在第二个窗口出现之前，因此用户输入单词并单击“提交”的可能性为 0%。将return移至函数末尾。

window.mainloop()
return (word, definition)

现在，您将在 click2 中收到 NameError: name 'entry1' is not Defined，因为在一个函数中定义的变量在另一个函数中不可见。重构 libraryentry 以使用类，因此 self 的属性可以在方法之间共享。

from tkinter import *

class DefinitionWindow(Toplevel):
    def __init__(self, root, click_callback):
        Toplevel.__init__(self, root)
        self.click_callback = click_callback
        self.title("Library entry")

        #Create the Label
        Label(self, text="Enter the word you want to add:").grid(row=0, column=0, sticky=W)

        #create entry box
        self.word_entry=Entry(self, width=20, bg="light green")
        self.word_entry.grid(row=1, column=0, sticky=W)

        #create second label
        Label(self, text="\nDefinition").grid(row=2, column=0, sticky=W)

        #create entry box
        self.definition_entry = Entry(self, width=50, bg="light green")
        self.definition_entry.grid(row=3, column=0, sticky=W)

        #create submit button
        Button(self, text="Submit", width=5, command=self.clicked).grid(row=4, column=0, sticky=W)

    def clicked(self):
        self.click_callback(self.word_entry.get(), self.definition_entry.get())
        self.destroy()

除了 OO 结构之外，请注意没有返回单词和定义的 main。这是由于 Tkinter 的异步特性 - 如果 main 等待定义窗口关闭，则 window.mainloop 无法继续执行，并且一切都会挂起。因此有必要注册一个回调，一旦用户做出选择，该回调就会在将来的某个时间执行。

def clickentry():
    def definition_submitted(word, definition):
        my_glossary[word] = definition

    definition_window = libraryentry.DefinitionWindow(window, definition_submitted)

结果: