Считывать данные с entry

from tkinter import *
from tkinter import messagebox
 
 
def show_message():
    messagebox.showinfo("пример ввода\вывода", message.get())
 
 
root = Tk()
root.title("пример ввода\вывода")
root.geometry("300x250")
 
message = StringVar()
 
message_entry = Entry(textvariable=message)
message_entry.place(relx=.5, rely=.1, anchor="c")
 
message_button = Button(text="Click Me", command=show_message)
message_button.place(relx=.5, rely=.5, anchor="c")
 
root.mainloop()

# calculator using Tkinter 
 
# import everything from tkinter module 
from tkinter import *
 
# globally declare the expression variable 
expression = ""
 
 
# Function to update expressiom 
# in the text entry box 
def press(num):
    # point out the global expression variable 
    global expression
 
    # concatenation of string 
    expression = expression + str(num)
 
    # update the expression by using set method 
    equation.set(expression)
 
 
# Function to evaluate the final expression 
def equalpress():
    # Try and except statement is used 
    # for handling the errors like zero 
    # division error etc. 
 
    # Put that code inside the try block 
    # which may generate the error 
    try:
 
        global expression
 
        # eval function evaluate the expression 
        # and str function convert the result 
        # into string 
        total = str(eval(expression))
 
        equation.set(total)
 
        # initialze the expression variable 
        # by empty string 
        expression = ""
 
        # if error is generate then handle
    # by the except block 
    except:
 
        equation.set(" error ")
        expression = ""
 
    # Function to clear the contents
 
 
# of text entry box
def clear():
    global expression
    expression = ""
    equation.set("")
 
 
# Driver code 
if __name__ == "__main__":
    # create a GUI window 
    gui = Tk()
 
    # set the background colour of GUI window 
    gui.configure(background="light green")
 
    # set the title of GUI window 
    gui.title("Simple Calculator")
 
    # set the configuration of GUI window 
    gui.geometry("265x125")
 
    # StringVar() is the variable class 
    # we create an instance of this class 
    equation = StringVar()
 
    # create the text entry box for 
    # showing the expression . 
    expression_field = Entry(gui, textvariable=equation)
 
    # grid method is used for placing 
    # the widgets at respective positions 
    # in table like structure . 
    expression_field.grid(columnspan=4, ipadx=70)
 
    equation.set('enter your expression')
 
    # create a Buttons and place at a particular 
    # location inside the root window . 
    # when user press the button, the command or 
    # function affiliated to that button is executed . 
    button1 = Button(gui, text=' 1 ', fg='black', bg='red',
                     command=lambda: press(1), height=1, width=7)
    button1.grid(row=2, column=0)
 
    button2 = Button(gui, text=' 2 ', fg='black', bg='red',
                     command=lambda: press(2), height=1, width=7)
    button2.grid(row=2, column=1)
 
    button3 = Button(gui, text=' 3 ', fg='black', bg='red',
                     command=lambda: press(3), height=1, width=7)
    button3.grid(row=2, column=2)
 
    button4 = Button(gui, text=' 4 ', fg='black', bg='red',
                     command=lambda: press(4), height=1, width=7)
    button4.grid(row=3, column=0)
 
    button5 = Button(gui, text=' 5 ', fg='black', bg='red',
                     command=lambda: press(5), height=1, width=7)
    button5.grid(row=3, column=1)
 
    button6 = Button(gui, text=' 6 ', fg='black', bg='red',
                     command=lambda: press(6), height=1, width=7)
    button6.grid(row=3, column=2)
 
    button7 = Button(gui, text=' 7 ', fg='black', bg='red',
                     command=lambda: press(7), height=1, width=7)
    button7.grid(row=4, column=0)
 
    button8 = Button(gui, text=' 8 ', fg='black', bg='red',
                     command=lambda: press(8), height=1, width=7)
    button8.grid(row=4, column=1)
 
    button9 = Button(gui, text=' 9 ', fg='black', bg='red',
                     command=lambda: press(9), height=1, width=7)
    button9.grid(row=4, column=2)
 
    button0 = Button(gui, text=' 0 ', fg='black', bg='red',
                     command=lambda: press(0), height=1, width=7)
    button0.grid(row=5, column=0)
 
    plus = Button(gui, text=' + ', fg='black', bg='red',
                  command=lambda: press("+"), height=1, width=7)
    plus.grid(row=2, column=3)
 
    minus = Button(gui, text=' - ', fg='black', bg='red',
                   command=lambda: press("-"), height=1, width=7)
    minus.grid(row=3, column=3)
 
    multiply = Button(gui, text=' * ', fg='black', bg='red',
                      command=lambda: press("*"), height=1, width=7)
    multiply.grid(row=4, column=3)
 
    divide = Button(gui, text=' / ', fg='black', bg='red',
                    command=lambda: press("/"), height=1, width=7)
    divide.grid(row=5, column=3)
 
    equal = Button(gui, text=' = ', fg='black', bg='red',
                   command=equalpress, height=1, width=7)
    equal.grid(row=5, column=2)
 
    clear = Button(gui, text='Clear', fg='black', bg='red',
                   command=clear, height=1, width=7)
    clear.grid(row=5, column='1')
 
    # start the GUI 
    gui.mainloop()