When trying to convert Entry to Int, it gives an error invalid literal for int() with base 10: '' How to fix?

Question

Python

Hello, I want to make a calculator that will calculate the data of a Rectangular Triangle
. But I get an error when converting the Entry type to the Int type.
What should I do?

Answer 1

Your function is called before you enter a value.
try is not used
You can try at least like this:

Button1=Button(text="Вычислить второй катет треугольника", command=Lambda:but1)