Tkinter provides numerous of universal widget methods or basic widget methods which works almost with all the available widgets.
winfo_ismapped() method -
This method is used to check whether the specified widget is visible or not. However, in this example, right after packing the widget back, the winfo_ismapped() method still returns the widget to be not mapped (false). Only after you clicked the button the second consecutive time it will update to be mapped (True).
Syntax: widget.winfo_ismapped()
Return Value: Returns True if widget is visible (or mapped), otherwise returns False.
Exception: If widget is destroyed, then it throws error.
Puython# Imports tkinter and ttk modulefromtkinterimport*fromtkinter.ttkimport*importtime# toplevel windowroot=Tk()defforget(widget):widget.forget()print("After Forget method called. Is widget mapped? = ",bool(widget.winfo_ismapped()))defretrieve(widget):widget.pack()print("After retrieval of widget. Is widget mapped? = ",bool(widget.winfo_ismapped()))# Button widgetsb1=Button(root,text="Btn 1")b1.pack()# This is used to make widget invisibleb2=Button(root,text="Btn 2",command=lambda:forget(b1))b2.pack()# This will retrieve widgetb3=Button(root,text="Btn 3",command=lambda:retrieve(b1))b3.pack()# infinite loop, interrupted by keyboard or mousemainloop()Output:
After first Btn 2 Press:
After First Btn 3 Press:
After Second Btn 3 Press:
winfo_exists() method -
This method is used to check if the specified widget exists or not i.e if the widget is destroyed or not.
Syntax: widget.winfo_exists()
Return value: Returns True if widget exists, False otherwise.
Python# Imports tkinter and ttk modulefromtkinterimport*fromtkinter.ttkimport*# toplevel windowroot=Tk()defdest(widget):widget.destroy()print("Destroy method called. Widget exists? = ",bool(widget.winfo_exists()))defexist(widget):print("Checking for existence = ",bool(widget.winfo_exists()))# Button widgetsb1=Button(root,text="Btn 1")b1.pack()# This is used to destroy widgetb2=Button(root,text="Btn 2",command=lambda:dest(b1))b2.pack()# This is used to check existence of the widgetb3=Button(root,text="Btn 3",command=lambda:exist(b1))b3.pack()# infinite loop, interrupted by keyboard or mousemainloop()Output:
Note: If a widget is destroyed it cannot be retrieved again.