Refactor the following python code. Focus on clear, simple code. Reduce redundancies and remember that the class is part of a bigger codebase. Use one-line docstrings and modern python features where appropriate. Python 3.12 Code: class Header:
    """Class for handling header UI."""

    DATA_TYPE_OPTIONS = ["string", "integer", "float", "boolean"]

    def __init__(self, root: tk.Tk, app: 'TableApp'):
        self.root = root
        self.app = app
        self.style = app.style
        self.colors = app.colors
        self.fonts = app.fonts
        self.dimensions = app.dimensions
        self.table_name_label = None
        self.lower_header_frame = None
        self.result = None
        self._setup_header()

    def _setup_header(self) -> None:
        header_frame = self._setup_main_frame()
        self._setup_upper_section(header_frame)
        self._setup_lower_section(header_frame)

    def _setup_main_frame(self) -> tk.Frame:
        header_frame = create_frame(parent=self.root, width=None, bg=self.colors["background"])
        header_frame.grid(row=0, column=1, columnspan=2, sticky="ew")
        header_frame.config(height=self.dimensions["header_height"])
        header_frame.grid_propagate(False)
        header_frame.grid_rowconfigure(0, weight=0)
        header_frame.grid_rowconfigure(1, weight=0)
        for i in range(5):
            header_frame.grid_columnconfigure(i, weight=1 if i == 4 else 0)
        return header_frame

    def _setup_upper_section(self, parent: tk.Frame) -> None:
        upper_frame = create_frame(parent=parent, width=None, bg=self.colors["background"])
        upper_frame.grid(row=0, column=0, columnspan=6, sticky="ew", pady=(0, 10))
        upper_frame.grid_columnconfigure(5, weight=1)
        self._add_upper_content(upper_frame)

    def _add_upper_content(self, frame: tk.Frame) -> None:
        tk.Label(
            frame,
            text="Data > ",
            bg=self.colors["background"],
            fg=self.colors["header_info"],
            font=self.fonts["header_info"]
        ).grid(row=0, column=0, padx=22, pady=(22, 0), sticky="nw")

        self.table_name_label = tk.Label(
            frame,
            text=self.app.current_table_name or "No Table Selected",
            bg=self.colors["background"],
            fg=self.colors["text"],
            font=self.fonts["header_info"]
        )
        self.table_name_label.grid(row=0, column=0, padx=(88, 10), pady=(22, 0), sticky="nw")

        self._setup_settings_section(frame)

    def _setup_settings_section(self, frame: tk.Frame) -> None:
        settings_container = tk.Frame(frame, bg=self.colors["background"])
        settings_container.grid(row=0, column=5, padx=(0, 40), pady=(22, 0), sticky="ne")

        common_label_options = {
            'bg': self.colors["background"],
            'fg': self.colors["text"],
            'font': self.fonts["text"],
            'cursor': "hand2",
            'width': 2,
            'height': 1
        }

        buttons_frame = tk.Frame(settings_container, bg=self.colors["background"])
        buttons_frame.pack(side=tk.LEFT)

        label_s = tk.Label(buttons_frame, text="S", **common_label_options)
        label_i = tk.Label(buttons_frame, text="I", **common_label_options)
        label_e = tk.Label(buttons_frame, text="E", **common_label_options)
        label_d = tk.Label(buttons_frame, text="D", **common_label_options)

        label_s.pack(side=tk.LEFT)
        label_i.pack(side=tk.LEFT)
        label_e.pack(side=tk.LEFT)
        label_d.pack(side=tk.LEFT)

        label_s.bind("<Button-1>", lambda e: self.show_stats())
        label_i.bind("<Button-1>", lambda e: self.app.table_io.import_file())
        label_e.bind("<Button-1>", lambda e: self.app.table_io.export_table())
        label_d.bind("<Button-1>", lambda e: self.show_datatype_dialog())

        def on_label_enter(event):
            widget = event.widget
            widget.config(bg=self.colors["button_selected"])

        def on_label_leave(event):
            widget = event.widget
            widget.config(bg=self.colors["background"])

        labels = [label_s, label_i, label_e, label_d]

        for label in labels:
            label.bind("<Enter>", on_label_enter)
            label.bind("<Leave>", on_label_leave)

    def _setup_lower_section(self, parent: tk.Frame) -> None:
        self.lower_header_frame = create_frame(parent=parent, width=None, bg=self.colors["background"])
        self.lower_header_frame.grid(row=1, column=0, columnspan=5, sticky="ew")

    def show_stats(self):
        """Display stats about the boolean columns in a menu-like popup with a table."""
        table_name = self.app.current_table_name
        if not table_name:
            messagebox.showwarning("No Table Selected", "Please select a table to view stats.")
            return

        if not self.app.current_sheet:
            messagebox.showwarning("No Data", "No data available to show stats.")
            return

        data = self.app.current_sheet.get_sheet_data()
        current_headers = self.app.current_sheet.headers()
        data_types = self.app.data_manager.tables_data[table_name].get("data_types", [])

        while len(data_types) < len(current_headers):
            data_types.append('string')

        total_rows = len(data)
        boolean_columns = []
        for col_idx, dtype in enumerate(data_types):
            if dtype == 'boolean':
                header = current_headers[col_idx]
                column_data = [bool(row[col_idx]) if row[col_idx] is not None else False for row in data]
                true_count = sum(1 for val in column_data if val is True)
                false_count = sum(1 for val in column_data if val is False)
                boolean_columns.append((header, true_count, false_count))

        if hasattr(self, 'stats_popup') and self.stats_popup.winfo_exists():
            self.stats_popup.destroy()

        self.stats_popup = tk.Toplevel(self.root)
        self.stats_popup.overrideredirect(True)

        border_frame = tk.Frame(self.stats_popup, bg=self.colors["frame_border"])
        border_frame.pack(padx=0, pady=0, expand=True, fill=tk.BOTH)

        content_frame = tk.Frame(border_frame, bg=self.colors["background"])
        content_frame.pack(padx=1, pady=1, expand=True, fill=tk.BOTH)

        inner_frame = tk.Frame(content_frame, bg=self.colors["background"])
        inner_frame.pack(padx=10, pady=10, expand=True, fill=tk.BOTH)

        total_label = tk.Label(
            inner_frame,
            text=f"Number of Rows: {total_rows}",
            bg=self.colors["background"],
            fg=self.colors["text"],
            font=self.fonts["menu"]
        )
        total_label.pack(pady=(0, 5), anchor='center')

        separator = tk.Frame(inner_frame, bg=self.colors["separator_menu"], height=1)
        separator.pack(fill=tk.X, pady=(0, 5))

        if boolean_columns:
            table_frame = tk.Frame(inner_frame, bg=self.colors["background"])
            table_frame.pack()

            headers = ["Column", "True", "False"]
            for col_num, header_text in enumerate(headers):
                header_label = tk.Label(
                    table_frame,
                    text=header_text,
                    bg=self.colors["background"],
                    fg=self.colors["text"],
                    font=self.fonts["menu"]
                )
                header_label.grid(row=0, column=col_num, padx=10, pady=2, sticky='w')

            for row_num, (header, true_count, false_count) in enumerate(boolean_columns, start=1):
                header_label = tk.Label(
                    table_frame,
                    text=header,
                    bg=self.colors["background"],
                    fg=self.colors["header_info"],
                    font=self.fonts["menu"]
                )
                header_label.grid(row=row_num, column=0, padx=10, pady=2, sticky='w')

                true_label = tk.Label(
                    table_frame,
                    text=str(true_count),
                    bg=self.colors["background"],
                    fg=self.colors["header_info"],
                    font=self.fonts["menu"]
                )
                true_label.grid(row=row_num, column=1, padx=10, pady=2, sticky='w')

                false_label = tk.Label(
                    table_frame,
                    text=str(false_count),
                    bg=self.colors["background"],
                    fg=self.colors["header_info"],
                    font=self.fonts["menu"]
                )
                false_label.grid(row=row_num, column=2, padx=10, pady=2, sticky='w')

            for col_num in range(3):
                table_frame.grid_columnconfigure(col_num, weight=1)
        else:
            no_data_label = tk.Label(
                inner_frame,
                text="No boolean columns to display.",
                bg=self.colors["background"],
                fg=self.colors["text"],
                font=self.fonts["menu"]
            )
            no_data_label.pack(pady=10)

        self.stats_popup.update_idletasks()

        popup_width = self.stats_popup.winfo_width()
        popup_height = self.stats_popup.winfo_height()

        screen_width = self.root.winfo_screenwidth()
        screen_height = self.root.winfo_screenheight()

        menu_x = self.root.winfo_pointerx()
        menu_y = self.root.winfo_pointery()

        padding = 10

        if menu_x + popup_width > screen_width - padding:
            menu_x = screen_width - popup_width - padding
        if menu_y + popup_height > screen_height - padding:
            menu_y = screen_height - popup_height - padding

        menu_x = max(padding, menu_x)
        menu_y = max(padding, menu_y)

        self.stats_popup.geometry(f"+{menu_x}+{menu_y}")

        def close_popup(event=None):
            if self.stats_popup.winfo_exists():
                self.stats_popup.destroy()
                self.root.unbind("<Button-1>", self.click_outside_popup)
                self.root.unbind("<Configure>", self.window_resized)

        def click_outside_popup(event):
            if not str(event.widget).startswith(str(self.stats_popup)):
                close_popup()

        self.click_outside_popup = self.root.bind("<Button-1>", click_outside_popup)
        self.window_resized = self.root.bind("<Configure>", lambda e: close_popup())

        self.stats_popup.bind("<FocusOut>", close_popup)
        self.stats_popup.bind("<Escape>", close_popup)

        self.stats_popup.focus_force()

    def update_true_counter(self, count_text: str) -> None:
        pass

    def show_datatype_dialog(self) -> None:
        """Show custom popup window for changing column data types."""
        table_name = self.app.current_table_name
        if not table_name:
            messagebox.showwarning("No Table Selected", "Please select a table to change datatypes.")
            return
    
        current_headers = self.app.current_sheet.headers() if self.app.current_sheet else []
        self.app.data_manager.headers[table_name] = current_headers
        self.data_types = self.app.data_manager.tables_data[table_name].get("data_types", []).copy()
        while len(self.data_types) < len(current_headers):
            self.data_types.append('string')
    
        if hasattr(self, 'datatype_popup') and self.datatype_popup.winfo_exists():
            self.datatype_popup.destroy()
    
        self.datatype_popup = tk.Toplevel(self.root)
        self.datatype_popup.overrideredirect(True)
    
        self.dropdown = None
    
        border_frame = tk.Frame(self.datatype_popup, bg=self.colors["frame_border"])
        border_frame.pack(padx=0, pady=0, expand=True, fill=tk.BOTH)
        content_frame = tk.Frame(border_frame, bg=self.colors["background"])
        content_frame.pack(padx=1, pady=1, expand=True, fill=tk.BOTH)
        inner_frame = tk.Frame(content_frame, bg=self.colors["background"])
        inner_frame.pack(padx=10, pady=10, expand=True, fill=tk.BOTH)
    
        self.datatype_vars = {}
    
        for header_index, header in enumerate(current_headers):
            current_type = self.data_types[header_index]
            frame = tk.Frame(inner_frame, bg=self.colors["background"])
            frame.pack(fill=tk.X, pady=0)
    
            header_label = tk.Label(
                frame,
                text=f"{header}:",
                bg=self.colors["background"],
                fg=self.colors["text"],
                font=self.fonts["menu"]
            )
            header_label.pack(side=tk.LEFT, padx=(0, 10))
    
            var = tk.StringVar(value=current_type)
            dropdown_button = tk.Label(
                frame,
                textvariable=var,
                bg=self.colors["background"],
                fg=self.colors["header_info"],
                font=self.fonts["menu"],
                cursor="hand2",
                width=6,
                anchor='w'
            )
            dropdown_button.pack(side=tk.RIGHT)

            def on_enter(e, btn=dropdown_button):
                btn.config(bg=self.colors["button_selected"])
    
            def on_leave(e, btn=dropdown_button):
                btn.config(bg=self.colors["background"])
    
            dropdown_button.bind("<Enter>", on_enter)
            dropdown_button.bind("<Leave>", on_leave)
    
            def create_dropdown(header, var, button):
                def show_dropdown(event):
                    if self.dropdown is not None and self.dropdown.winfo_exists():
                        self.dropdown.destroy()
                        self.dropdown = None
    
                    x = button.winfo_rootx()
                    y = button.winfo_rooty() + button.winfo_height()
                    dropdown = tk.Toplevel(self.datatype_popup)
                    self.dropdown = dropdown
                    dropdown.overrideredirect(True)
                    dropdown.geometry(f"+{x}+{y}")
    
                    border_frame = tk.Frame(dropdown, bg=self.colors["frame_border"])
                    border_frame.pack(padx=0, pady=0, expand=True, fill=tk.BOTH)
    
                    inner_frame = tk.Frame(border_frame, bg=self.colors["background"])
                    inner_frame.pack(padx=1, pady=1, expand=True, fill=tk.BOTH)
    
                    for option in self.DATA_TYPE_OPTIONS:
                        option_label = tk.Label(
                            inner_frame,
                            text=option,
                            bg=self.colors["background"],
                            fg=self.colors["header_info"],
                            font=self.fonts["menu"],
                            anchor='w',
                            width=6
                        )
                        option_label.pack(fill=tk.X)
    
                        def on_enter(e, lbl=option_label):
                            lbl.config(bg=self.colors["button_selected"])
    
                        def on_leave(e, lbl=option_label):
                            lbl.config(bg=self.colors["background"])
    
                        option_label.bind("<Enter>", on_enter)
                        option_label.bind("<Leave>", on_leave)
    
                        def on_option_select(e, opt=option):
                            var.set(opt)
                            dropdown.destroy()
                            self.dropdown = None
                            return "break"
    
                        option_label.bind("<Button-1>", on_option_select)
    
                    dropdown.bind("<Button-1>", lambda e: "break")
                    dropdown.focus_force()
                    return "break"
    
                button.bind("<Button-1>", show_dropdown)
                button.bind("<Button-1>", lambda e: "break", add="+")
    
            create_dropdown(header, var, dropdown_button)
            self.datatype_vars[header] = var

        separator = tk.Frame(inner_frame, bg=self.colors["separator_menu"], height=1)
        separator.pack(fill=tk.X, pady=(5, 5))

        apply_container = tk.Frame(
            inner_frame, bg=self.colors["background"], cursor="hand2"
        )
        apply_container.pack(fill=tk.X, pady=(5, 0))

        apply_label = tk.Label(
            apply_container,
            text="Apply Changes",
            bg=self.colors["background"],
            fg=self.colors["text"],
            font=self.fonts["menu"],
            cursor="hand2"
        )
        apply_label.pack(expand=True, fill=tk.BOTH, pady=0)

        def on_hover_enter(event):
            apply_container.config(bg=self.colors["button_selected"])
            apply_label.config(bg=self.colors["button_selected"])

        def on_hover_leave(event):
            apply_container.config(bg=self.colors["background"])
            apply_label.config(bg=self.colors["background"])

        apply_container.bind("<Enter>", on_hover_enter)
        apply_container.bind("<Leave>", on_hover_leave)
        apply_label.bind("<Enter>", on_hover_enter)
        apply_label.bind("<Leave>", on_hover_leave)
        apply_container.bind("<Button-1>", lambda e: self._apply_changes())
        apply_label.bind("<Button-1>", lambda e: self._apply_changes())

        self.datatype_popup.update_idletasks()
        popup_width = self.datatype_popup.winfo_width()
        popup_height = self.datatype_popup.winfo_height()
        screen_width = self.root.winfo_screenwidth()
        screen_height = self.root.winfo_screenheight()
        menu_x = self.root.winfo_pointerx()
        menu_y = self.root.winfo_pointery()
        padding = 10

        if menu_x + popup_width > screen_width - padding:
            menu_x = screen_width - popup_width - padding
        if menu_y + popup_height > screen_height - padding:
            menu_y = screen_height - popup_height - padding

        menu_x = max(padding, menu_x)
        menu_y = max(padding, menu_y)
        self.datatype_popup.geometry(f"+{menu_x}+{menu_y}")

        def is_descendant(widget, ancestor):
            while widget:
                if widget == ancestor:
                    return True
                widget = widget.master
            return False

        def close_dropdown(event=None):
            if self.dropdown is not None and self.dropdown.winfo_exists():
                self.dropdown.destroy()
                self.dropdown = None

        def close_popup(event=None):
            if self.datatype_popup.winfo_exists():
                self.datatype_popup.destroy()
            close_dropdown()
            self.root.unbind("<Button-1>", self.click_outside_popup)
            self.root.unbind("<Configure>", self.window_resized)

        def click_outside_popup(event):
            if not is_descendant(event.widget, self.datatype_popup):
                close_popup()

        def on_datatype_popup_click(event):
            if self.dropdown is not None and self.dropdown.winfo_exists():
                if not is_descendant(event.widget, self.dropdown):
                    close_dropdown()
                    return "break"
            return None

        self.datatype_popup.bind("<Button-1>", on_datatype_popup_click)
        self.click_outside_popup = self.root.bind("<Button-1>", click_outside_popup)
        self.window_resized = self.root.bind("<Configure>", lambda e: close_popup())
        self.datatype_popup.bind("<Escape>", close_popup)
        self.datatype_popup.focus_force()

    def _apply_changes(self) -> None:
        """Apply the datatype changes and update the table."""
        table_name = self.app.current_table_name
        current_headers = self.app.current_sheet.headers() if self.app.current_sheet else []
        self.data_types = []

        for header in current_headers:
            dtype = self.datatype_vars[header].get()
            self.data_types.append(dtype)

        self.app.data_manager.tables_data[table_name]["data_types"] = self.data_types
        self.app.data_manager.save_data()
        self.app.table_display.apply_column_data_types(self.data_types)
        self.app.table_display.process_and_save_current_sheet_data()
        self.app.refresh_table()
        if hasattr(self, 'datatype_popup') and self.datatype_popup.winfo_exists():
            self.datatype_popup.destroy()