如何交換tkinter按鈕之間的數據幀？

Question

我很新的python編程，這是我的第一個問題，所以請溫和我。現在我正在研究一種讀取CSV文件的tkinter GUI，將它們轉換爲數據幀以編輯它們，並將處理後的文件保存到數據路徑中的result.csv中。我的問題是，我想用一個連接到一個按鈕的函數OpenFile（）讀取CSV，然後在我的「Editfunctions」中使用返回的數據框，每個按鈕都連接到一個按鈕。這似乎不起作用，我的代碼中回調。這裏是我的Tkinter GUI目前的樣子：

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() 

MY功能基本上是這樣的：

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() 

所以我認爲不正常的是，回調不移交數據框讀從OpenFile（）到EditFile（z）。我怎麼能做到這一點？ 感謝您的幫助！

Answer 1

command=執行功能，但它不關心從該函數返回的值，所以你必須使用global變量來使用其他函數中的一個函數的結果。

你的代碼看起來是這樣的

#!/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() 

或者學習如何使用類和self.代替global