why my list changes to a string as I move to another window in tkinter?-CodePudding

I wrote an app using that basis learned there, and this app reads a text file and removes the redundant lines, and returns a list of numbers. The code below returns a list of numbers in PageOne, But as I want to use that list in PageTwo, it changes to a string. I know I have initially introduced variables as strings, but it does not work under other types as well. How I can keep that as a list? To run this code you can put a few numbers with space separation in a text file and open it using the app.

import tkinter as tk
from tkinter import filedialog
 
 
class Data:
    def __init__(self):
        self.Tot_grids = tk.IntVar()
        self.NO = tk.StringVar()
        self.NEW = tk.StringVar()
        self.NEW2 = tk.StringVar()
 
 
class SampleApp(tk.Tk):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.geometry("500x200")
 
        container = tk.Frame(self)
        container.pack()
 
        self.data = Data()
 
        self.frames = {}
        for F in (PageOne, PageTwo):
            frame = F(container, self.data)
            self.frames[F] = frame
            frame.grid(row=0, column=0, sticky="nsew")
 
        self.frames[PageOne].button2.config(command=self.go_to_page_two)
        self.show_frame(PageOne)
 
    def go_to_page_two(self):
        self.show_frame(PageTwo)
 
    def show_frame(self, c):
        frame = self.frames[c]
        frame.tkraise()
 
 
class PageOne(tk.Frame):
    def __init__(self, parent, data):
        super().__init__(parent)
        self.data = data
 
        def opentext():
            my_file = filedialog.askopenfilenames(initialdir="/pycharm", title="Select your file")
            for T in my_file:  # this line should be here when opening multiple files
                import re
                with open(T, 'r') as infile1:
                    lines = infile1.read()
 
                    nums = []
                    for n in re.findall(r'(\d \.\d |\d \*\d )', lines):
                        split_by_ast = n.split("*")
                        if len(split_by_ast) == 1:
                            nums  = [float(split_by_ast[0])]
                        else:
                            nums  = [float(split_by_ast[1])] * int(split_by_ast[0])
                nums = nums[1:len(nums)]
                data.NO.set(nums)
                label3.config(text=nums)
                label4.config(text=type(nums))
 
        self.button1 = tk.Button(self, text="Open file(s)", command=opentext)
        self.button1.grid(row=0, column=0, columnspan=2, pady=20)
 
        label1 = tk.Label(self, text="imported numbers:")
        label1.grid(row=1, column=0, pady=10)
 
        label2 = tk.Label(self, text="type of imported numbers:")
        label2.grid(row=2, column=0, pady=5)
 
        label3 = tk.Label(self)
        label3.grid(row=1, column=1)
 
        label4 = tk.Label(self)
        label4.grid(row=2, column=1, pady=5)
 
        self.button2 = tk.Button(self, text="Continue")
        self.button2.grid(row=3, column=0, columnspan=2, pady=10)
 
class PageTwo(tk.Frame):
    def __init__(self, parent, data):
        super().__init__(parent)
        self.data = data
 
        self.label5 = tk.Label(self, textvariable=self.data.NEW)
        self.label5.pack()
 
        self.label5 = tk.Label(self, textvariable=self.data.NEW2)
        self.label5.pack()
 
        self.data.NO.trace_add('write', self.on_grids_updated)
 
    def on_grids_updated(self, *args):
        self.data.NEW.set(self.data.NO.get())
        self.data.NEW2.set(type(self.data.NO.get()))
 
app = SampleApp()
app.mainloop()

I also wondered why the type of list in PageOne is shown with some random numbers? thanks

CodePudding user response：

You can use Variable which is the base class of StringVar, IntVar, etc.

Variable.get() does not convert the stored data like StringVar.get() or IntVar.get(). However it seems that list will be converted to tuple by TCL internally.

class Data:
    def __init__(self):
        self.Tot_grids = tk.IntVar()
        self.NO = tk.Variable()  # used Variable instead of StringVar
        self.NEW = tk.StringVar()
        self.NEW2 = tk.StringVar()

Also change the line

label4.config(text=type(nums))

label4.config(text=str(type(nums)))

will show the type correctly.