hey,
this is coldsober irene.

this package is about checking or tracking if the data written in the tkinter entry widget is the whole or float number
not a string or else datatype.

you only need to create a double var and use it to track the data as you type in the entry widget.

this is my github repository, you can see the sample code 
https://github.com/coldsober-irene/tracknumber/tree/main