我添加了一个线程，以便程序在等待用户输入编辑内容时不会挂起。您可能需要添加一个或多个文本框来输入编辑内容

import tkinter as tk
import tkinter.ttk as ttk
import threading

root = tk.Tk()

tview = ttk.Treeview(root)
tview["columns"] = ("SLOT_1", "SLOT_2")
tview.column("SLOT_1", width=100)
tview.column("SLOT_2", width=100)

tview.heading("#0", text="Column 0", anchor="w")
tview.heading("SLOT_1", text="Column 1")
tview.heading("SLOT_2", text="Column 2")

def test_program_thread():
    thread = threading.Thread(None, edit_item, None, (), {})
    thread.start()

def add_item():
    tview.insert("", "end", values=("", "bar"))

def edit_item():
    focused = tview.focus()
    x = input('Enter a Value you want to change')
    tview.insert("", str(focused)[1:], values=("", str(x)))
    tview.delete(focused)

tview.pack()

add_item = tk.Button(root, text="Add item", command=add_item)
add_item.pack(expand=True, fill='both')

edit_item_button = tk.Button(root, text="Edit item", command=test_program_thread)
edit_item_button.pack(expand=True, fill='both')

root.mainloop()

基于Gardener85's answer构建。
使用单个.item更新行，而不是使用.insert添加新行，然后使用.delete删除旧行，这将有助于处理包含9行以上的树视图，并使更新的行保持在树视图中的相同位置。
修改后的Gardener85's answer的完整代码：

tview = ttk.Treeview(root)
tview["columns"] = ("SLOT_1", "SLOT_2")
tview.column("SLOT_1", width=100)
tview.column("SLOT_2", width=100)

tview.heading("#0", text="Column 0", anchor="w")
tview.heading("SLOT_1", text="Column 1")
tview.heading("SLOT_2", text="Column 2")

def test_program_thread():
    thread = threading.Thread(None, edit_item, None, (), {})
    thread.start()

def add_item():
    tview.insert("", "end", values=("", "bar"))

def edit_item():
    focused = tview.focus()
    x = input('Enter a Value you want to change')
    tview.item(focused, values=("", str(x)))

tview.pack()

add_item = tk.Button(root, text="Add item", command=add_item)
add_item.pack(expand=True, fill='both')

edit_item_button = tk.Button(root, text="Edit item", command=test_program_thread)
edit_item_button.pack(expand=True, fill='both')

root.mainloop()

要仅更新TTK TreeView中的特定单元格，无需按照建议删除和重新插入。而是调用TreeView的“set”方法

tree.set(my_row_id, column=my_column_id, value=my_new_value)