为什么在打印时使用python中的tkinter将输入表示为对象？

Question

I am writing a program that will take skill names as input from text entries and calculate the corresponding value of all of the skills entered. When I enter a skill in the program and then print the skill to the shell it appears as an object? Why does this happen and how can I fix it, do I need a repr or str ? Why doesn't the delete method to clear the text entry work as well?

import tkinter as tk
from tkinter import ttk

#make the lists to store the skill names
floorEle1Skills = []

class startValue(tk.Tk):

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

        tk.Tk.__init__(self, *args, **kwargs)

        tk.Tk.wm_title(self, "Start Value Calculator")
        tk.Tk.minsize(self, width = 350, height = 300)

        container = tk.Frame(self)
        container.pack(side = 'top', fill = 'both', expand = True)
        container.grid_rowconfigure(0, weight = 1)
        container.grid_columnconfigure(0, weight = 1)

        self.frames = {}

        for f in (startPage, floorPage, pommelPage, ringsPage, vaultPage, pbarsPage, hbarPage):

            frame = f(container, self)

            self.frames[f] = frame

            frame.grid(row = 0, column = 0, sticky = "nsew")

        self.showFrame(startPage)

        #make the lists to store the skill names
        floorEle1Skills = []

    def showFrame(self, cont):

        frame = self.frames[cont]
        frame.tkraise()

    def floorEle1(skill):
        floorEle1Skills.append(skill)
        #clear the text entry
        #ele1Entry.delete(0, tk.END)
        #why doesnt this work???
        #why is it printed as an object??
        print(floorEle1Skills)


class startPage(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        label = tk.Label(self, text = "Select Event")
        label.pack(pady = 10, padx = 10)

        floorButton = ttk.Button(self, text = "Floor", command = lambda : controller.showFrame(floorPage))
        floorButton.pack()


class floorPage(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        label = tk.Label(self, text = "Floor")
        label.pack(pady = 10, padx = 10)

        #make the entries and labels
        ele1Label = tk.Label(self, text = "Element Group 1:")
        ele1Label.pack()
        skill1 = tk.StringVar()
        ele1Entry = tk.Entry(self, textvariable = skill1)
        ele1Entry.pack()
        ele1Button = ttk.Button(self, text = "Add", command = lambda : controller.floorEle1())
        ele1Button.pack()

        startButton = ttk.Button(self, text = "Back to Start", command = lambda : controller.showFrame(startPage))
        startButton.pack(side = 'bottom')

Answer 1

Welcome to Python. The problem is in the function floorEle1(skill) . This is a member function of class startValue , but the argument list doesn't begin with self . Python doesn't force you to name the first variable self ; you can actually name it whatever you want (but don't do it!). So within this function the variable named skill acts just like the variable self . It's exactly as if you had written this:

def floorEle1(self):
    floorEle1Skills.append(self)
    #clear the text entry
    #ele1Entry.delete(0, tk.END)
    #why doesnt this work???
    #why is it printed as an object??
    print(floorEle1Skills)

I think you can see now that your code, in effect, appends self to floorEle1Skills; ie, you append the instance of your main window! So when you print the list, the print statement shows that the list contains an object.

Answer 2

As already mentioned in the another answer the problem with the code turns around the function floorEle1(self, skill) , BUT ... there are also some other issues that should be properly addressed in order to get the entered skills passed to the list of skills (see code below):

import tkinter as tk
from tkinter import ttk

#make the lists to store the skill names
# floorEle1Skills = []

class startValue(tk.Tk):

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

        tk.Tk.__init__(self, *args, **kwargs)

        tk.Tk.wm_title(self, "Start Value Calculator")
        tk.Tk.minsize(self, width = 350, height = 300)

        container = tk.Frame(self)
        container.pack(side = 'top', fill = 'both', expand = True)
        container.grid_rowconfigure(0, weight = 1)
        container.grid_columnconfigure(0, weight = 1)

        self.frames = {}

        for f in (startPage, floorPage): # , pommelPage, ringsPage, vaultPage, pbarsPage, hbarPage):

            frame = f(container, self)

            self.frames[f] = frame

            frame.grid(row = 0, column = 0, sticky = "nsew")

        self.showFrame(startPage)

        #make the lists to store the skill names
        self.floorEle1Skills = []

    def showFrame(self, cont):

        self.floorEle1Skills = []
        frame = self.frames[cont]
        frame.tkraise()

    def floorEle1(self, skill):
        print("#", skill.get())
        self.floorEle1Skills.append(skill)
        #clear the text entry
        #ele1Entry.delete(0, tk.END)
        #why doesnt this work???
        #why is it printed as an object??
        for item in self.floorEle1Skills:
            print("##",item.get())


class startPage(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        label = tk.Label(self, text = "Select Event")
        label.pack(pady = 10, padx = 10)

        floorButton = ttk.Button(self, text = "Floor", command = lambda : controller.showFrame(floorPage))
        floorButton.pack()


class floorPage(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        label = tk.Label(self, text = "Floor")
        label.pack(pady = 10, padx = 10)

        #make the entries and labels
        ele1Label = tk.Label(self, text = "Element Group 1:")
        ele1Label.pack()
        skill1 = tk.StringVar()
        ele1Entry = tk.Entry(self, textvariable = skill1)
        ele1Entry.pack()
        ele1Button = ttk.Button(self, text = "Add", command = lambda : controller.floorEle1(ele1Entry))
        ele1Button.pack()

        startButton = ttk.Button(self, text = "Back to Start", command = lambda : controller.showFrame(startPage))
        startButton.pack(side = 'bottom')

root = tk.Tk()
my_gui = startValue()
root.mainloop()

Other changes in the code are:

definition of self.floorEle1Skills = [] in the '__ init __()' function and passing the appropriate parameter to controller.floorEle1(ele1Entry) so that the input string value is passed to the function handling the button push.

The above code prints the user input to the terminal (twice, first from the passed user input, second all items in the list).

Placing self.floorEle1Skills = [] line in showFrame() resets the list collecting the input of skills (making restart of input possible).

The code above solves both issues addressed in the question, but this doesn't mean that there are not further issues needing to be solved.