Updating tkinter label value dynamically without using button

I know how to update the label with the command assigned to the button. but I want it to do this dynamically with entry inputs, without buttons.

i want to change label value dynamically while user input entries.

example function is;

def calculation():

    a = var2.get() \* var3.get()
    var1.set(a)

import tkinter as tk

def calculation(event=None):
    try:
        if input_entry1.get() and input_entry2.get():
            a = float(input_entry1.get()) * float(input_entry2.get())
            output_label["text"]=a
    except ValueError:
        output_label["text"] = "Please enter numbers only"

root=tk.Tk()
input_entry1=tk.Entry(root)
input_entry1.pack()
input_entry2=tk.Entry(root)
input_entry2.pack()
output_label=tk.Label(root)
output_label.pack()
input_entry1.bind("<KeyRelease>", calculation)
input_entry2.bind("<KeyRelease>", calculation)
root.mainloop()

Hope this helps.