Hey there! I totally get the frustration when pack_forget() or destroy() doesn't behave like you expect—this is a super common gotcha when working with Tkinter (I assume that's what you're using, given the pack methods mentioned). Let's break down why your current approach isn't working and how to fix it.

The Core Issue #

Chances are, you're either:

• Not saving references to the dynamically created Label/Entry widgets (so you can't target them later to hide/destroy), or
• Trying to destroy widgets that weren't properly initialized as instance variables in your class.

Solution 1: Pre-Create & Toggle Visibility (Recommended) #

Instead of creating/destroying widgets every time the radio button changes, it's cleaner to pre-make the file input components and just toggle their visibility. Wrapping them in a single Frame makes this even easier—you only need to show/hide the Frame instead of individual widgets.

Here's a working example:

import tkinter as tk
from tkinter import ttk

class SimulationApp(tk.Tk):
    def __init__(self):
        super().__init__()
        self.title("Simulation Controller")
        
        # Track selected simulation type
        self.selected_sim = tk.StringVar(value="random")
        
        # Build radio button frame
        radio_container = ttk.Frame(self)
        radio_container.pack(pady=10, padx=20)
        
        ttk.Radiobutton(
            radio_container,
            text="随机模拟",
            variable=self.selected_sim,
            value="random",
            command=self.toggle_file_input
        ).pack(side="left", padx=10)
        
        ttk.Radiobutton(
            radio_container,
            text="文件输入模拟",
            variable=self.selected_sim,
            value="file",
            command=self.toggle_file_input
        ).pack(side="left", padx=10)
        
        # Pre-create file input widgets (hidden initially)
        self.file_input_frame = ttk.Frame(self)
        self.file_label = ttk.Label(self.file_input_frame, text="文件名:")
        self.file_label.pack(side="left", padx=5)
        self.file_entry = ttk.Entry(self.file_input_frame, width=35)
        self.file_entry.pack(side="left", padx=5)
        
        # Start with file input hidden
        self.file_input_frame.pack_forget()
    
    def toggle_file_input(self):
        if self.selected_sim.get() == "file":
            # Show the file input frame
            self.file_input_frame.pack(pady=10, padx=20)
        else:
            # Hide the file input frame
            self.file_input_frame.pack_forget()

if __name__ == "__main__":
    app = SimulationApp()
    app.mainloop()

Why This Works: #

• All file-related widgets are stored as instance variables (self.file_input_frame, etc.), so we always have a reference to them.
• Wrapping everything in a Frame means we only need to call pack()/pack_forget() once per toggle, instead of managing multiple widgets.

Solution 2: Dynamic Create & Destroy #

If you really need to create and destroy widgets on the fly (instead of just hiding them), you have to save references to every widget you create. Otherwise, you won't be able to target them for destruction later.

Here's how to do it:

import tkinter as tk
from tkinter import ttk

class SimulationApp(tk.Tk):
    def __init__(self):
        super().__init__()
        self.title("Simulation Controller")
        
        self.selected_sim = tk.StringVar(value="random")
        self.file_widgets = None  # Store references to dynamic widgets
        
        radio_container = ttk.Frame(self)
        radio_container.pack(pady=10, padx=20)
        
        ttk.Radiobutton(
            radio_container,
            text="随机模拟",
            variable=self.selected_sim,
            value="random",
            command=self.switch_sim_type
        ).pack(side="left", padx=10)
        
        ttk.Radiobutton(
            radio_container,
            text="文件输入模拟",
            variable=self.selected_sim,
            value="file",
            command=self.switch_sim_type
        ).pack(side="left", padx=10)
    
    def switch_sim_type(self):
        if self.selected_sim.get() == "file":
            # Only create widgets if they don't exist yet
            if not self.file_widgets:
                frame = ttk.Frame(self)
                label = ttk.Label(frame, text="文件名:")
                entry = ttk.Entry(frame, width=35)
                
                label.pack(side="left", padx=5)
                entry.pack(side="left", padx=5)
                frame.pack(pady=10, padx=20)
                
                # Save references to all widgets
                self.file_widgets = (frame, label, entry)
        else:
            # Destroy widgets if they exist
            if self.file_widgets:
                for widget in self.file_widgets:
                    widget.destroy()
                # Reset the reference so we can create them again later
                self.file_widgets = None

if __name__ == "__main__":
    app = SimulationApp()
    app.mainloop()

Why Your Previous Attempt Failed: #

If you were creating widgets like ttk.Label(...) without assigning them to self.something, Python would garbage-collect the reference immediately. That means when you tried to call destroy() later, there was no way to find the widget to delete it.

Final Notes #

• Stick with Solution 1 if you can—toggling visibility is more efficient and less error-prone than creating/destroying widgets repeatedly.
• Always store dynamic widgets as instance variables if you need to modify them later (hide, destroy, update text, etc.).

内容的提问来源于stack exchange，提问作者Suri