from tkinter import *
from tkinter import filedialog
import sys

def cmopen():
 file_path = filedialog.askopenfilename()
 f=open(file_path, "r")
 text.insert(0.0, f.read())
 f.close()

def cmsave():
 file = filedialog.asksaveasfile(defaultextension='.txt')
 print(file.name)
 lines=text.get(0.0, END)
 print(lines)
 f = open(file.name, 'w')
 f.write(lines)
 f.close
def cmexit():
 exit()
def setsizefont(stext):
 global text
 text['font'] = ('Arial',int(stext) , 'bold')
def winsize():
  window = Tk()
  window.title("Размер шрифта")
  window.geometry("500x300")
  e1 = Entry(window,width=50,text="20")
  e1.insert(0, "25")
  e1.pack()
  b1 = Button(window,text="Изменить", width=15, height=3,command=lambda: setsizefont(e1.get()))
  b1.pack()

root = Tk()
root.geometry('500x500')
root.title("Ptext")
scrollbar = Scrollbar(root)

text = Text(root, yscrollcommand = scrollbar.set ,wrap=WORD,width=50,font= ('Arial', 16, 'bold'))
text.place(x = 0 , y = 0)

mainmenu = Menu(root) 
root.config(menu=mainmenu) 
filemenu = Menu(mainmenu, tearoff=0)
filemenu.add_command(label="Открыть файл",command=cmopen)
filemenu.add_command(label="Сохранить",command=cmsave)
filemenu.add_command(label="Выход",command=cmexit)
mainmenu.add_cascade(label="Команды", menu=filemenu)
 
fmenu = Menu(mainmenu, tearoff=0)
fmenu.add_command(label="Размер шрифта",command=winsize)
mainmenu.add_cascade(label="Форматирование",menu=fmenu)

root.mainloop()