main.py

def stud_academics(window):
    window.destroy()

#def stud_academics() -> None:
    customtkinter.set_appearance_mode("dark")
    customtkinter.set_default_color_theme("dark-blue")

    # Creating text variable for subject, examination
    global sub_var
    global examintaion

    # Creating academics window
    saw = customtkinter.CTk()
    saw.geometry("1280x585")
    saw.resizable(0,0)

    sub_var = StringVar()
    examination_var = StringVar()

    saw.title("STUDENT ACADEMICS")
    saw.iconbitmap("./ico/stud_academics.ico")

    # Creating background image variable
    bg = ImageTk.PhotoImage(Image.open("./icons/academics.jpg").resize((1280, 720), Image.Resampling.LANCZOS))

    # Creating background image label
    l1 = customtkinter.CTkLabel(master=saw, image=bg, bg_color="black")
    l1.place(x=0, y=0)

    # Creating the subject text label
    l2 = customtkinter.CTkLabel(master=saw, text="SUBJECT", text_font=("Consolas", 20, "bold"))
    l2.place(x=1070, y=40)

    # Getting student stream from database
    stream = L[6]

    # Creating combobox
    cb1 = customtkinter.CTkComboBox(master=saw)

    if stream == "computer science":
        cb1["values"] = ["Computer Science", "Maths", "Chemistry", "Physics, English"]

    elif stream == "bio maths":
        cb1["values"] = ["Biology", "Maths", "Chemistry", "Physics", "English"]

    elif stream == "bio psychology":
        cb1["values"] = ["Biology", "Psychology", "Chemistry", "Physics", "English"]

    elif stream == "commerce computer":
        cb1["values"] = ["Commerce", "Bussiness", "Economics", "Accountancy", "Computer Science"]

    elif stream == "commerce ip":
        cb1["values"] = ["Commerce", "Bussiness", "Economics", "Accountancy", "IP"]

    elif stream == "commerce maths":
        cb1["values"] = ["Commerce", "Bussiness", "Economics", "Accountancy", "Maths"]

    cb1.place(x=1070, y=60)

    saw.mainloop()