Python 3：_tkinter.TclError：无效的命令名称“。！scrollbar”

Question

I'm new to python programming and I'm trying to create two scrollable frames for time series data but none of them are activating when I add dynamic frames. Each frame contains 3 parts that displays the variables in column 1, plot in column 2 and unique dates in row 3 Snapshot of the GUI . I'm getting the following error:

    Exception in Tkinter callback
    Traceback (most recent call last):
      File "C:\Users\ranji\Anaconda3\lib\tkinter\__init__.py", line 1702, in __call__
        return self.func(*args)
      File "C:\Users\ranji\Anaconda3\lib\tkinter\__init__.py", line 3069, in set
        self.tk.call(self._w, 'set', first, last)
    _tkinter.TclError: invalid command name ".!scrollbar"
    Exception in Tkinter callback
    Traceback (most recent call last):
      File "C:\Users\ranji\Anaconda3\lib\tkinter\__init__.py", line 1702, in __call__
        return self.func(*args)
      File "C:\Users\ranji\Anaconda3\lib\tkinter\__init__.py", line 3069, in set
        self.tk.call(self._w, 'set', first, last)
    _tkinter.TclError: invalid command name ".!scrollbar2"

Could any of you help me find the source of the error?

Below is my code:

    import os
    import tkinter as tk
    #from tkinter import ttk
    from tkinter import filedialog as fd
    import pandas as pd
    import matplotlib.pyplot as plt
    from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg

    def on_configure(event):
        # update scrollregion after starting 'mainloop'
        canvas1.configure(scrollregion=canvas1.bbox('all'))
        canvas2.configure(scrollregion=canvas2.bbox('all'))

    root = tk.Tk()
    root.geometry('{}x{}'.format(800, 600))

    # layout all of the main containers
    root.grid_rowconfigure(1, weight=1)
    root.grid_columnconfigure(0, weight=1)


    #Global variables
    category = tk.StringVar()
    global rownum
    rownum =0
    mindatetime = pd.to_datetime('1900-01-01 00:00:00')
    maxdatetime = pd.to_datetime('1900-01-01 00:00:00')

    def enterCategory():
        global cat
        cat = category.get()
        global catmainframe
        global rownum
        global add_file

        catmainframe = tk.Frame(canvas1, borderwidth=2, relief="solid")
        catmainframe.grid(row=rownum,column=0,sticky='nsew', padx=3, pady=3)

        catmainframe.grid_rowconfigure(0, weight=1)
        catmainframe.grid_columnconfigure(0, weight=1)     
        catframe = tk.Frame(catmainframe, borderwidth=2, relief="solid")
        catframe.grid(row=0,column=0, sticky='nsew', padx=1, pady=1)

        catlabel = tk.Label(catframe, text=cat)
        catlabel.grid(row=0, column=0, sticky='nsew')

        add_file = tk.Button(catframe,text="Add File",command=openFile)
        add_file.grid(row=0, column=1, sticky='nsew')

        global catchildframe
        catchildframe = tk.Frame(catmainframe, borderwidth=2, relief="solid")
        catchildframe.grid(row=1,column=0,sticky='nsew', padx=1, pady=1)
        catchildframe.grid_rowconfigure(1, weight=1)
        catchildframe.grid_columnconfigure(1, weight=1)  
        global box1, box2, box3
        box1 = tk.Frame(catchildframe, borderwidth=2, relief="solid")
        box2 = tk.Frame(catchildframe, borderwidth=2, relief="solid")
        box3 = tk.Frame(catchildframe, borderwidth=2, relief="solid")
        box1.grid(row=1, column=0, sticky='nsew', padx=10, pady=10)
        box2.grid(row=1, column=1, sticky='nsew', padx=10, pady=10)
        box3.grid(row=1, column=2, sticky='nsew', padx=10, pady=10)
        box1.propagate(1)
        box2.propagate(1)
        box3.propagate(1)

        rownum =  rownum +1

    def openFile():
        parentname = catmainframe.winfo_parent()
        parent = catmainframe._nametowidget(parentname)

        #childname = catchildframe.winfo_parent()
        #child = catchildframe._nametowidget(childname)
        child = add_file.master

        print("Catmainframe parent:"+parentname)
        #print("Catchildframe parent:"+child)
        global fname
        global mindatetime
        global maxdatetime
        file_path=fd.askopenfilename()
        #print(file_path)

        file_name = os.path.basename(file_path)
        print(file_name)

        file_list = []

        file_list.append(file_name)

        df = pd.read_csv(file_path)
        names = list(df.columns[0:])
        indexcol = names[0]
        #print(indexcol)
        df = df.rename(columns = {indexcol:'datetime'})
        names = list(df.columns[1:])
        #print(names)
        df.datetime = pd.to_datetime(df.datetime)
        df.set_index('datetime',inplace=True)

        if mindatetime == pd.to_datetime('1900-01-01 00:00:00'):
            mindatetime = df.index.min()
        elif mindatetime > df.index.min():
            mindatetime = df.index.min()

        if maxdatetime == pd.to_datetime('1900-01-01 00:00:00'):
            maxdatetime = df.index.max()
        elif maxdatetime < df.index.max():
            maxdatetime = df.index.max()

        print(mindatetime)
        print(maxdatetime)    
        global unique_dates
        unique_dates = []
        unique_dates = df.index.map(pd.Timestamp.date).unique()

        for x in range(len(names)):    
            if(len(names)==1):
                l = tk.Checkbutton(box1, text=names[x], variable=names[x],state='disabled')
                l.select()
                l.pack(anchor = 'w')
            else:
                l = tk.Checkbutton(box1, text=names[x], variable=names[x])
                l.select()
                l.pack(anchor = 'w')

        figure = plt.Figure(figsize=(5,4), dpi=100)
        ax2 = figure.add_subplot(111)
        line = FigureCanvasTkAgg(figure, box2)
        line.get_tk_widget().grid(row=1,column=1,sticky='nsew')
        df.plot(kind='line', legend=False, ax=ax2, fontsize=10)
        ax2.set_title(cat)
        ax2.set_xlim(mindatetime,maxdatetime)

        for x in range(len(unique_dates)):
            d = tk.Checkbutton(box3, text=unique_dates[x], variable=unique_dates[x])
            d.select()
            d.pack(anchor = 'w')

    #Top frame
    top_frame = tk.Frame(root)
    top_frame.grid(row=0, column=0, sticky='nsew')

    category_name = tk.Label(top_frame, text='Category:')
    category_name.grid(row=0, column=0, sticky='nsew')

    entry_category = tk.Entry(top_frame, background="pink",textvariable = category)
    entry_category.grid(row=0, column=1, sticky='nsew')
    entry_category.focus()

    ok_button = tk.Button(top_frame, text="OK", command=enterCategory)
    ok_button.grid(row=0, column=2, sticky='nsew')

    xscrollbar = tk.Scrollbar(root, orient='horizontal')
    xscrollbar.grid(row=3, column=0, sticky='ew')

    yscrollbar = tk.Scrollbar(root)
    yscrollbar.grid(row=1, column=1, sticky='ns')

    canvas1 = tk.Canvas(root, bd=0,#scrollregion=(0, 0, 1000, 1000),
                    yscrollcommand=yscrollbar.set)
    canvas1.grid(row=1, column=0, sticky='nsew')

    # create the center widgets
    canvas1.grid_rowconfigure(1, weight=1)
    canvas1.grid_columnconfigure(0, weight=1)

    canvas2 = tk.Canvas(root, bd=0,#scrollregion=(0, 0, 1000, 1000),
                    xscrollcommand=xscrollbar.set)
    canvas2.grid(row=2, column=0, sticky='nsew')

    xscrollbar.config(command=canvas2.xview)
    yscrollbar.config(command=canvas1.yview)


    canvas1.config(scrollregion=canvas1.bbox("all"))

    canvas2.config(scrollregion=canvas2.bbox("all"))

    root.mainloop()

Answer 1

You already know this but I put all in one place

---

To add widget to Canvas you have to use

 canvas.create_window(position, window=widget) 

instead of grid() .

If you don't use create_window() then canvas is empty and scrollbars have nothing to scroll.

catmainframe = tk.Frame(canvas1, borderwidth=2, relief="solid")
canvas1.create_window((0,0), window=catmainframe, anchor='nw') #, width=750)

You have to also add

root.bind('<Configure>', on_configure) 

to run function which will update scrollbar's information how big area is to scroll.

You can add it directly before root.mainloop()

---

Code which I used to tests - with some other cleanups: all function at the beginning of code, all global at the beginning of functions.

import os
import tkinter as tk
from tkinter import filedialog as fd
import pandas as pd
import matplotlib.pyplot as plt
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg

# --- functions ---
# all functions at the beginning to make it more readable

def on_configure(event):
    # update scrollregion after starting 'mainloop'
    canvas1.configure(scrollregion=canvas1.bbox('all'))
    canvas2.configure(scrollregion=canvas2.bbox('all'))

def enterCategory():
    # all `global` at the beginning to make it more readable
    global cat
    global catmainframe
    global rownum
    global add_file
    global catchildframe
    global box1, box2, box3

    cat = category.get()

    catmainframe = tk.Frame(canvas1, borderwidth=2, relief="solid")
    canvas1.create_window((0,0), window=catmainframe, anchor='nw')#, width=750)

    catmainframe.grid_rowconfigure(0, weight=1)
    catmainframe.grid_columnconfigure(0, weight=1)     

    catframe = tk.Frame(catmainframe, borderwidth=2, relief="solid")
    catframe.grid(row=0,column=0, sticky='nsew', padx=1, pady=1)

    catlabel = tk.Label(catframe, text=cat)
    catlabel.grid(row=0, column=0, sticky='nsew')

    add_file = tk.Button(catframe, text="Add File", command=openFile)
    add_file.grid(row=0, column=1, sticky='nsew')

    catchildframe = tk.Frame(catmainframe, borderwidth=2, relief="solid")
    catchildframe.grid(row=1,column=0,sticky='nsew', padx=1, pady=1)
    catchildframe.grid_rowconfigure(1, weight=1)
    catchildframe.grid_columnconfigure(1, weight=1)  
    box1 = tk.Frame(catchildframe, borderwidth=2, relief="solid")
    box2 = tk.Frame(catchildframe, borderwidth=2, relief="solid")
    box3 = tk.Frame(catchildframe, borderwidth=2, relief="solid")
    box1.grid(row=1, column=0, sticky='nsew', padx=10, pady=10)
    box2.grid(row=1, column=1, sticky='nsew', padx=10, pady=10)
    box3.grid(row=1, column=2, sticky='nsew', padx=10, pady=10)
    box1.propagate(1)
    box2.propagate(1)
    box3.propagate(1)

    rownum += 1

def openFile():
    # all `global` at the beginning to make it more readable
    global fname
    global mindatetime
    global maxdatetime
    global unique_dates

    parentname = catmainframe.winfo_parent()
    parent = catmainframe._nametowidget(parentname)

    #childname = catchildframe.winfo_parent()
    #child = catchildframe._nametowidget(childname)
    child = add_file.master

    print("Catmainframe parent:", parentname)
    #print("Catchildframe parent:"+child)
    file_path = fd.askopenfilename()
    #print(file_path)

    file_name = os.path.basename(file_path)
    print(file_name)

    file_list = []

    file_list.append(file_name)

    df = pd.read_csv(file_path)
    names = list(df.columns[0:])
    indexcol = names[0]
    #print(indexcol)
    df = df.rename(columns = {indexcol:'datetime'})
    names = list(df.columns[1:])
    #print(names)
    df.datetime = pd.to_datetime(df.datetime)
    df.set_index('datetime', inplace=True)

    if mindatetime == pd.to_datetime('1900-01-01 00:00:00'):
        mindatetime = df.index.min()
    elif mindatetime > df.index.min():
        mindatetime = df.index.min()

    if maxdatetime == pd.to_datetime('1900-01-01 00:00:00'):
        maxdatetime = df.index.max()
    elif maxdatetime < df.index.max():
        maxdatetime = df.index.max()

    print(mindatetime)
    print(maxdatetime)    
    unique_dates = []
    unique_dates = df.index.map(pd.Timestamp.date).unique()

    for x in range(len(names)):    
        l = tk.Checkbutton(box1, text=names[x], variable=names[x])
        if len(names) == 1:
            l['state'] = 'disabled'
        l.select()
        l.pack(anchor='w')

    figure = plt.Figure(figsize=(5,4), dpi=100)
    ax2 = figure.add_subplot(111)
    line = FigureCanvasTkAgg(figure, box2)
    line.get_tk_widget().grid(row=1, column=1, sticky='nsew')
    df.plot(kind='line', legend=False, ax=ax2, fontsize=10)
    ax2.set_title(cat)
    ax2.set_xlim(mindatetime,maxdatetime)

    for x in range(len(unique_dates)):
        d = tk.Checkbutton(box3, text=unique_dates[x], variable=unique_dates[x])
        d.select()
        d.pack(anchor='w')

# --- main ---

# global is used only inside function to inform function 
# that you want to use external/global variable when you assign value
# and then it doesn't create local variable
#global rownum # not needed # all variables created outside functionsa  are glboal

root = tk.Tk()
root.geometry('{}x{}'.format(800, 600))

# layout all of the main containers
root.grid_rowconfigure(1, weight=1)
root.grid_columnconfigure(0, weight=1)

#Global variables
category = tk.StringVar()
rownum = 0
mindatetime = pd.to_datetime('1900-01-01 00:00:00')
maxdatetime = pd.to_datetime('1900-01-01 00:00:00')

#Top frame
top_frame = tk.Frame(root)
top_frame.grid(row=0, column=0, sticky='nsew')

category_name = tk.Label(top_frame, text='Category:')
category_name.grid(row=0, column=0, sticky='nsew')

entry_category = tk.Entry(top_frame, background="pink",textvariable = category)
entry_category.grid(row=0, column=1, sticky='nsew')
entry_category.focus()

ok_button = tk.Button(top_frame, text="OK", command=enterCategory)
ok_button.grid(row=0, column=2, sticky='nsew')

xscrollbar = tk.Scrollbar(root, orient='horizontal')
xscrollbar.grid(row=3, column=0, sticky='ew')

yscrollbar = tk.Scrollbar(root)
yscrollbar.grid(row=1, column=1, sticky='ns')

canvas1 = tk.Canvas(root, bd=0,#scrollregion=(0, 0, 1000, 1000),
                yscrollcommand=yscrollbar.set)
canvas1.grid(row=1, column=0, sticky='nsew')

# create the center widgets
canvas1.grid_rowconfigure(1, weight=1)
canvas1.grid_columnconfigure(0, weight=1)

canvas2 = tk.Canvas(root, bd=0,#scrollregion=(0, 0, 1000, 1000),
                xscrollcommand=xscrollbar.set)
canvas2.grid(row=2, column=0, sticky='nsew')

xscrollbar.config(command=canvas2.xview)
yscrollbar.config(command=canvas1.yview)

root.bind('<Configure>', on_configure)

root.mainloop()