将ttk.Notebook（）选项卡居中时出现问题

Question

I'm trying to create a simple GUI in order to solve structures.

The aim is to let the user add tabs to the GUI if he/she wants to start another project even if a tab is already opened.

My main problem right now is that when a tab is created according the following code, it is centered instead of being created from left to right:

import tkinter as tk
from tkinter import ttk

class Pytures(ttk.Frame):

    def __init__(self, main_window):
        super().__init__(main_window)
        #Title
        main_window.title("Pytures 0.1.1")
        #Geometry initialation
        width = main_window.winfo_screenwidth()
        height = main_window.winfo_screenheight()
        scSize = str(width) + 'x' + str(height)
        main_window.geometry(scSize)

        #Calls the MenuBar function during initialation
        self.MenuBar(main_window)

        #Initialize first blank tab -> Tab1
        self.notebook = ttk.Notebook(self)
        self.tab_names = {}
        self.tabAttr_names = {}

        self.TabClassCreator()
        self.TabAttributeCreator()

        self.pack()

    def TabClassCreator(self):
        # It creates new tab classes 
        global how_many_tabs
        how_many_tabs = len(self.tab_names)

        if how_many_tabs >= 1:
            self.tab_names[how_many_tabs] = 'Tab'+str(how_many_tabs+1)
            exec('global {0}\nclass {0}(ttk.Frame):\n\tdef __init__(self, *args, **kwargs):\n\t\tsuper().__init__(*args, **kwargs)'.format(self.tab_names[how_many_tabs]))
        else:

            self.tab_names[0] = 'Tab1'

            exec('global {0}\nclass {0}(ttk.Frame):\n\tdef __init__(self, *args, **kwargs):\n\t\tsuper().__init__(*args, **kwargs)'.format(self.tab_names[0]))

        print('Is the class TabN created?')
        print('Class TabN created-> {}'.format(eval(self.tab_names[how_many_tabs])))

    def TabAttributeCreator(self):
        # It creates new tab attributes
        if how_many_tabs >= 1:
            self.tabAttr_names[how_many_tabs] = 'Tab_'+str(how_many_tabs+1)
            exec('self.{0} = {1}(self.notebook)'.format(self.tabAttr_names[how_many_tabs], self.tab_names[how_many_tabs]))
            self.notebook.add(eval('self.{0}'.format(self.tabAttr_names[how_many_tabs])), text=self.tab_names[how_many_tabs])
            self.notebook.pack(expand=1, fill="both")
        else:
            self.tabAttr_names[0] = 'Tab_1'
            exec('self.{0} = {1}(self.notebook)'.format(self.tabAttr_names[0], self.tab_names[0]))
            self.notebook.add(eval('self.{0}'.format(self.tabAttr_names[0])), text=self.tab_names[0])
            self.notebook.pack(expand=1, fill="both")
            print('Attribute Tab_N created-> '+str(eval('self.Tab_1')))
        return eval('self.{}'.format(self.tabAttr_names[how_many_tabs]))

    def MenuBar(self, main_window):

        global menubar

        menubar = tk.Menu(main_window)
        filemenu = tk.Menu(menubar, tearoff=0)
        filemenu.add_command(label="New (ctrl + n)", command=None)#newTab) #command=create_tab.createTab(tabControl)
        filemenu.add_command(label="Open (ctrl + o)", command=None)
        filemenu.add_command(label="Save (ctrl + s)", command=None)
        filemenu.add_command(label="Save as...", command=None) #saveAs
        filemenu.add_command(label="Close (ctrl + k)", command=None)#closeTab)

        filemenu.add_separator()

        filemenu.add_command(label="Exit", command=self.quit)
        menubar.add_cascade(label="File", menu=filemenu)
        editmenu = tk.Menu(menubar, tearoff=0)
        editmenu.add_command(label="Undo", command=None)

        editmenu.add_separator()

        editmenu.add_command(label="Cut", command=None)
        editmenu.add_command(label="Copy", command=None)
        editmenu.add_command(label="Paste", command=None)
        editmenu.add_command(label="Delete", command=None)
        editmenu.add_command(label="Select All", command=None)

        menubar.add_cascade(label="Edit", menu=editmenu)
        helpmenu = tk.Menu(menubar, tearoff=0)
        helpmenu.add_command(label="Help Index", command=None)
        helpmenu.add_command(label="About...", command=None)
        menubar.add_cascade(label="Help", menu=helpmenu)


        main_window.config(menu=menubar)

if __name__=="__main__":
    global main_window, app
    main_window = tk.Tk()
    app = Pytures(main_window)
    app.mainloop()

I wrote it based in this code:

import tkinter as tk
from tkinter import ttk

class Application(ttk.Frame):

    def __init__(self, main_window):
        super().__init__(main_window)

        main_window.title("Panel de pestañas en Tcl/Tk")

        self.notebook = ttk.Notebook(self)

        self.greeting_frame = GreetingFrame(self.notebook)
        self.notebook.add(self.greeting_frame, text="Saludos", padding=10)

        self.about_frame = AboutFrame(self.notebook)
        self.notebook.add(self.about_frame, text="Acerca de", padding=10)

        self.notebook.pack(padx=10, pady=10)
        self.pack()

        print(self.greeting_frame)
        type(self.greeting_frame)
        print(self.about_frame)
        type(self.about_frame)
        print(self.notebook)
        type(self.notebook)

class GreetingFrame(ttk.Frame):

    def __init__(self, *args, **kwargs):

        print('Hola GreetingFrame')
        super().__init__(*args, **kwargs)

        self.name_entry = ttk.Entry(self)
        self.name_entry.pack()

        self.greet_button = ttk.Button(
            self, text="Saludar", command=self.say_hello)
        self.greet_button.pack()

        self.greet_label = ttk.Label(self)
        self.greet_label.pack()

    def say_hello(self):
        print(self.greet_button)
        self.greet_label["text"] = \
            "¡Hola, {}!".format(self.name_entry.get())

class AboutFrame(ttk.Frame):

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        self.label = ttk.Label(self)
        self.label["text"] = ("Visitanos en recursospython.com y "
                              "foro.recursospython.com.")
        self.label.pack()

        self.web_button = ttk.Button(self, text="Visitar web")
        self.web_button.pack(pady=10)

        self.forum_button = ttk.Button(self, text="Visitar foro")
        self.forum_button.pack()



if __name__=="__main__":
    main_window = tk.Tk()
    app = Application(main_window)
    app.mainloop()

PD: I have choosen "exec()" despite being a newbie to create the new tabs because I think it is better to create only the tabs you need instead of creating a predetermined and limited number of hidden tabs that are raised when the user wants to create a new tab.

Answer 1

The reason this is happening is because you have pack() geometry manager which center aligns the widget.

Use grid() geometry manager instead.

Change this statement self.pack() to self.grid(row=0, column=0)