如何响应 tkinter 事件？

Question

我正在 python 中使用 GUI 做一些工作。我正在使用 Tkinter 库。

我需要一个按钮，它将打开一个 .txt 文件并进行以下处理：

frequencies = collections.defaultdict(int)    # <-----------------------
with open("test.txt") as f_in:                  
    for line in f_in:
        for char in line:
            frequencies[char] += 1
total = float(sum(frequencies.values()))      #<-------------------------

我开始：

from Tkinter import *               
import tkFileDialog,Tkconstants,collections

root = Tk()
root.title("TEST")
root.geometry("800x600")

button_opt = {'fill': Tkconstants.BOTH, 'padx': 66, 'pady': 5}
fileName = ''
def openFile():
    fileName = tkFileDialog.askopenfile(parent=root,title="Open .txt file", filetypes=[("txt file",".txt"),("All files",".*")])
Button(root, text = 'Open .txt file', fg = 'black', command= openFile).pack(**button_opt)



frequencies = collections.defaultdict(int)    # <-----------------------
with open("test.txt") as f_in:                  
    for line in f_in:
        for char in line:
            frequencies[char] += 1
total = float(sum(frequencies.values()))      #<-------------------------



root.mainloop()

现在我不知道如何组装我的代码，以便在按下按钮时运行。

Answer 1

主要问题是tkFileDialog.askopenfile() 返回一个打开的file 而不是文件名。以下似乎或多或少对我有用：

from Tkinter import *
import tkFileDialog, Tkconstants,collections

root = Tk()
root.title("TEST")
root.geometry("800x600")

def openFile():
    f_in = tkFileDialog.askopenfile(
                            parent=root,
                            title="Open .txt file",
                            filetypes=[("txt file",".txt"),("All files",".*")])

    frequencies = collections.defaultdict(int)
    for line in f_in:
        for char in line:
            frequencies[char] += 1
    f_in.close()
    total = float(sum(frequencies.values()))
    print 'total:', total

button_opt = {'fill': Tkconstants.BOTH, 'padx': 66, 'pady': 5}
fileName = ''
Button(root, text = 'Open .txt file',
       fg = 'black',
       command= openFile).pack(**button_opt)

root.mainloop()

为了快速创建简单的 GUI 程序，我强烈推荐 EasyGUI，一个相当强大但简单的基于 Tk 的 Python 模块，用于执行此类操作。

Answer 2

尝试一些类似这样的布局：

class my_app():
    def __init__():
        self.hi_there = Tkinter.Button(frame, text="Hello", command=self.say_hi)
        self.hi_there.pack(side=Tkinter.LEFT)

    def say_hi():
        # do stuff

您可能还想阅读：

This tutorial on Tkinter,

And this one.

编辑： OP 想要一个带有他的代码的示例（我认为）所以这里是：

from Tkinter import *               
import tkFileDialog,Tkconstants,collections

class my_app:
    def __init__(self, master):
        frame = Tkinter.Frame(master)
        frame.pack()

        self.button_opt = {'fill': Tkconstants.BOTH, 'padx': 66, 'pady': 5}
        self.button = Button(frame, text = 'Open .txt file', fg = 'black', command= self.openFile).pack(**button_opt)

        self.calc_button = Button(frame, text = 'Calculate', fg = 'black', command= self.calculate).pack()

        self.fileName = ''

    def openFile():
        fileName = tkFileDialog.askopenfile(parent=root,title="Open .txt file", filetypes=[("txt file",".txt"),("All files",".*")])

    def calculate():
        ############################################### *See note
        frequencies = collections.defaultdict(int)    # <-----------------------
        with open("test.txt") as f_in:                  
            for line in f_in:
               for char in line:
                   frequencies[char] += 1
        total = float(sum(frequencies.values()))      #<-------------------------
        ################################################

root = Tk()

app = App(root)

root.title("TEST")
root.geometry("800x600")

root.mainloop()

*注意：在您的代码中，我没有看到集合来自哪里，所以我不太确定如何处理该块。在此示例中，我已将其设置为在

Answer 3

在您的openFile() 函数中，在您向用户询问文件名之后，输入您的代码！