Why does tkinter PanedWindow.sash_place not work in bind_class?

I wanted to customize the way the sash on a tkinter PanedWindow looked based on if the user is clicking on it, so I cam up with this.

import tkinter as tk
from tkinter import ttk

class PanedTest(tk.Tk):
    def __init__(self, master = None) -> None:
        super().__init__(master)
        
        self.style = ttk.Style()
        
        self.style.configure('TPanedwindow', background='black')
        self.style.configure('Clicked.TPanedwindow', background='blue')
        self.style.configure('Sash', sashthickness = 8)
        
        self.bind_class('TPanedwindow', '<Button-1>', lambda e : e.widget.configure(style = 'Clicked.TPanedwindow'))
        self.bind_class('TPanedwindow', '<B1-Motion>', lambda e : e.widget.sash_place(0, e.x, e.y))
        self.bind_class('TPanedwindow', '<ButtonRelease-1>', lambda e : e.widget.configure(style = 'TPanedwindow'))
        
        self.paned1 = ttk.PanedWindow()
        self.paned1.pack()
        
        self.frame1 = ttk.Frame(self.paned1, width = 200, height = 200)
        self.paned1.add(self.frame1)
        
        self.frame2 = ttk.Frame(self.paned1, width = 200, height = 200)
        self.paned1.add(self.frame2)
        
        
        self.paned2 = ttk.PanedWindow(orient = 'horizontal')
        self.paned2.pack()
        
        self.frame3 = ttk.Frame(self.paned2, width = 200, height = 200)
        self.paned2.add(self.frame3)
        
        self.frame4 = ttk.Frame(self.paned2, width = 200, height = 200)
        self.paned2.add(self.frame4)
    
if __name__ == "__main__":
    app = PanedTest()
    app.mainloop()

Unfortunately, this results in an error

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Program Files\Python310\lib\tkinter\__init__.py", line 1921, in __call__
    return self.func(*args)
  File "paned_test.py", line 15, in <lambda>
    self.bind_class('TPanedwindow', '<B1-Motion>', lambda e : e.widget.sash_place(0, e.x, e.y))        
  File "C:\Program Files\Python310\lib\tkinter\__init__.py", line 4490, in sash_place
    return self.sash("place", index, x, y)
  File "C:\Program Files\Python310\lib\tkinter\__init__.py", line 4464, in sash
    self.tk.call((self._w, 'sash') + args)) or ()
_tkinter.TclError: wrong # args: should be ".!panedwindow2 sashpos index ?newpos?"

So after a lot of testing, I managed to get it to work with this

import tkinter as tk
from tkinter import ttk

class PanedTest(tk.Tk):
    def __init__(self, master = None) -> None:
        super().__init__(master)
        
        self.style = ttk.Style()
        
        self.style.configure('TPanedwindow', background='black')
        self.style.configure('Clicked.TPanedwindow', background='blue')
        self.style.configure('Sash', sashthickness = 8)
        
        self.bind_class('TPanedwindow', '<Button-1>', lambda e : e.widget.configure(style = 'Clicked.TPanedwindow'))
        self.bind_class('TPanedwindow', '<B1-Motion>', lambda e : e.widget.sash(0, (e.x if str(e.widget.cget('orient')) == 'horizontal' else e.y)))
        self.bind_class('TPanedwindow', '<ButtonRelease-1>', lambda e : e.widget.configure(style = 'TPanedwindow'))
        
        self.paned1 = ttk.PanedWindow()
        self.paned1.pack()
        
        self.frame1 = ttk.Frame(self.paned1, width = 200, height = 200)
        self.paned1.add(self.frame1)
        
        self.frame2 = ttk.Frame(self.paned1, width = 200, height = 200)
        self.paned1.add(self.frame2)
        
        
        self.paned2 = ttk.PanedWindow(orient = 'horizontal')
        self.paned2.pack()
        
        self.frame3 = ttk.Frame(self.paned2, width = 200, height = 200)
        self.paned2.add(self.frame3)
        
        self.frame4 = ttk.Frame(self.paned2, width = 200, height = 200)
        self.paned2.add(self.frame4)
    
if __name__ == "__main__":
    app = PanedTest()
    app.mainloop()

I can now drag the paned windows, but it does also give this error

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Program Files\Python310\lib\tkinter\__init__.py", line 1921, in __call__
    return self.func(*args)
  File "paned_test.py", line 48, in <lambda>
    self.bind_class('TPanedwindow', '<B1-Motion>', lambda e : e.widget.sash(0, (e.x if str(e.widget.cget('orient')) == 'horizontal' else e.y)))
  File "C:\Program Files\Python310\lib\tkinter\__init__.py", line 4463, in sash
    return self._getints(
  File "C:\Program Files\Python310\lib\tkinter\__init__.py", line 1467, in _getints
    return tuple(map(self.tk.getint, self.tk.splitlist(string)))
TypeError: splitlist() argument must be str, bytes or bytearray, not int

Here's the difference between the two scripts

self.bind_class('TPanedwindow', '<B1-Motion>', lambda e : e.widget.sash_place(0, e.x, e.y))

vs

self.bind_class('TPanedwindow', '<B1-Motion>', lambda e : e.widget.sash(0, (e.x if str(e.widget.cget('orient')) == 'horizontal' else e.y)))

Why does only the second one work, and not the function that is specifically for what I am trying to do?

oh, and converting e.widget.cget('orient') to str is just because the result is a <class '_tkinter.Tcl_Obj'>.

This may be a bug on tkinter. For your first code that uses e.widget.sash_place(0, e.x, e.y), it just internally calls self.sash('place', index, x, y) which raises the invalid number of arguments error because .sash() expects two arguments, index and pos, only (i.e. how you use .sash() in your second code block.

However inside .sash() it calls self._getints() on the result of self.tk.call(...) which is an integer, but self._getints() expects a string. That is what the second error means.

To avoid the second error, you can use e.widget.tk.call() directly instead of .sash():

self.bind_class('TPanedwindow', '<B1-Motion>',
                lambda e: e.widget.tk.call(e.widget, "sash", 0, (e.x if str(e.widget["orient"]) == "horizontal" else e.y)))