Question

我对python编程很新，这是我提出的第一个问题，所以要对我很温柔。现在我正在开发一个读取CSV文件的tkinter GUI，将它们转换为数据帧进行编辑，并将处理后的文件保存到数据路径中的result.csv中。我的问题是我想要用一个连接到一个按钮的功能OpenFile（）读取CSV，然后在我的＆＃34;编辑功能＆＃34;中使用返回的数据帧。每个也连接到一个按钮。这似乎不适用于代码中的回调。以下是我的tkinter GUI目前的样子：

root = tk.Tk()
openbutton = tk.Button (root, text='OpenFile', command = lambda: OpenFile())
openbutton.pack()
brakebutton = tk.Button (root, text = 'EditFile', command = lambda: EditFile(z))
brakebutton.pack()
savenewbutton = tk.Button(root, text = 'SavetoNewFile', command = lambda: SaveinNewFile(out_tup_end3))
savenewbutton.pack()
saveexcbutton = tk.Button(root, text = 'AppendtoExistingFile', command = lambda: SavetoexistingFile(out_tup_end3))
saveexcbutton.pack()
root.mainloop()

我的功能基本上是这样的：

def OpenFile():
      name = askopenfilename()
      df = pd.read_csv(name, sep = ';')
      return df

def EditFile(z):


        df1 = z[[]]
.
.
.
.
return out_tup_end3

def SaveinNewFile(out_tup_end3):
    out_tup_end3.to_csv("datapath", sep = ';', index = 0, mode = 'w')


def SavetoexistingFile(out_tup_end3):           
    with open("datapath", 'a') as f:
        out_tup_end3.to_csv(f, header=False, sep = ';', index = 0)


def main():   

    z = OpenFile()
    EditFile(z)
    editedFile = EditFile(z)
    SaveinNewFile(editedFile)
    SavetoexistingFile(editedFile)


if __name__ == "__main__":
   main()

所以我认为不正常工作的部分是回调没有将从OpenFile（）读取的dataFrame移交给EditFile（z）。我怎样才能实现这一目标？感谢您的帮助!!

Answer 1

command=执行函数但它并不关心从此函数返回的值，因此您必须使用global变量来使用其他函数中的一个函数的结果。

您的代码可能如下所示

#!/usr/bin/env python3

import tkinter as tk
from tkinter.filedialog import askopenfilename
from tkinter.messagebox import showinfo, showwarning
import pandas as pd

# --- functions ---

def open_file():
    # inform function to use global variables
    global df

    name = askopenfilename()

    if name:
        df = pd.read_csv(name, sep=';')
        showinfo("INFO", "DataFrame created")

def edit_file():
    # inform function to use global variables
    global df, out_tup_end3

    if df is None:
        #print("Read file first")
        showwarning("WARNING", "Read file first")
    else:
        df1 = df[[]]

        # ...

        out_tup_end3 = df1
        showinfo("INFO", "DataFrame edited")


def save_in_new_file():
    # inform function to use global variables
    global out_tup_end3

    if out_tup_end3 is None:
        #print("Read file first")
        showwarning("WARNING", "Read file first")
    else:
        out_tup_end3.to_csv("datapath", sep=';', index=0, mode='w')
        showinfo("INFO", "DataFrame saved")


def save_to_existing_file():           
    # inform function to use global variables
    global out_tup_end3

    if out_tup_end3 is None:
        #print("Read file first")
        showwarning("WARNING", "Read file first")
    else:
        with open("datapath", 'a') as f:
            out_tup_end3.to_csv(f, header=False, sep=';', index=0)
        showinfo("INFO", "DataFrame appended")


# --- main ---

if __name__ == "__main__":

    # create global variables

    df = None
    out_tup_end3 = None

    # GUI

    root = tk.Tk()

    b = tk.Button(root, text='Open File', command=open_file)
    b.pack(fill='x')

    b = tk.Button(root, text='Edit File', command=edit_file)
    b.pack(fill='x')

    b = tk.Button(root, text='Save to New File', command=save_in_new_file)
    b.pack(fill='x')

    b = tk.Button(root, text='Append to Existing File', command=save_to_existing_file)
    b.pack(fill='x')

    root.mainloop()

或了解如何使用课程和self.代替global

如何在tkinter按钮之间移交数据帧？

1 个答案: