completer点击选择改为双击选择，代码实现

可以通过更改 `Completer` 类的 `_listbox` 方法来实现将点击选择改为双击选择。具体实现代码如下：

import tkinter as tk
from tkinter import ttk


class DoubleClickCompleter(ttk.Entry):
    def __init__(self, master, options=[], **kwargs):
        super().__init__(master, **kwargs)

        self.options = sorted(options, key=str.lower) if options else []
        self.current_options = []
        self._listbox = None
        self._listbox_visible = False
        self._selected_index = None

        self.bind("<KeyRelease>", self._on_key_release)
        self.bind("<Return>", self._on_return)
        self.bind("<Button-1>", self._on_click)
        self.bind("<Double-Button-1>", self._on_double_click)

    def _on_key_release(self, event):
        """
        Event handler for key releases. Updates the listbox with the current options.
        """
        self.current_options = [
            option for option in self.options if self.get().lower() in option.lower()
        ]
        self._update_listbox()

    def _on_return(self, event):
        """
        Event handler for the return key. Inserts the selected option into the entry widget.
        """
        if self._listbox_visible:
            self.delete(0, tk.END)
            self.insert(0, self._listbox.get(tk.ACTIVE))
            self._listbox_visible = False
            self._listbox.destroy()
            self.icursor(tk.END)

    def _on_click(self, event):
        """
        Event handler for mouse clicks. Hides the listbox if it is visible.
        """
        if self._listbox_visible:
            self._listbox_visible = False
            self._listbox.destroy()

    def _on_double_click(self, event):
        """
        Event handler for double mouse clicks. Inserts the selected option into the entry widget.
        """
        if self._listbox_visible:
            self.delete(0, tk.END)
            self.insert(0, self._listbox.get(tk.ACTIVE))
            self._listbox_visible = False
            self._listbox.destroy()
            self.icursor(tk.END)

    def _update_listbox(self):
        """
        Updates the listbox with the current options.
        """
        if not self.current_options:
            if self._listbox_visible:
                self._listbox_visible = False
                self._listbox.destroy()
        else:
            if not self._listbox_visible:
                self._listbox = tk.Listbox(
                    master=self.master,
                    height=len(self.current_options),
                    exportselection=False,
                )
                self._listbox.bind("<Button-1>", self._on_click)
                self._listbox.place(
                    x=self.winfo_x(),
                    y=self.winfo_y() + self.winfo_height(),
                )

            self._listbox_visible = True
            self._listbox.delete(0, tk.END)
            for option in self.current_options:
                self._listbox.insert(tk.END, option)

在这个实现中，我们新增了一个 `_on_double_click` 方法，用于处理双击事件。同时在 `_on_click` 中也需要加入判断，避免在双击时出现不必要的操作。