How To Set My Widgets' Size And Padding Dynamically To Fit Window In Tkinter?

I am new to Tkinter and still learning. My desktop resolution is 1366x768 and I am developing for an environment which is 2048x768. Right now I am setting the window resolution by

Solution 1:

Now I have several screens and I cannot use grid on each and every screen.

Why can't you? There's nothing preventing you from using grid on every screen. Though, it's actually quite common to mix and match pack and grid in different frames, and arguably a best practice.

Like I have a Login Screen in which I have a Label like this...

The code following that statement doesn't have a Label, so it's hard to know what you are trying to do.

if I am running my application on a 640x480...

First you say you have a desktop resolution of 1366x768, then say you are targeting 2048x768, and are now asking about 640x480. That's a pretty wide range of values. If you have to support something as low as 640x480 you definitely should not be hard-coding padding to such huge values. Typically padding is never more than one or two. Tkinter apps can be made to accommodate that wide range of screen sizes, but that relies on not hard-coding the size of widgets and padding as much as possible.

How can I set these padx and pady and other width and height values dynamically according to the screen size and resolutions?

Generally speaking, you shouldn't do that. The general rule of thumb with tkinter is that you make the widgets the smallest size they need to be and let the geometry managers worry about stretching or shrinking them to fit the available space. There are a few exceptions to that rule, but in general, that rule works quite well.

Unfortunately, geometry management questions are hard to answer without knowing more about what you're trying to do. For example, we need to know why you think you need padding of 100 pixels. That seems highly unusual. Plus, we need to know what else is in your frame, what your frame is in, and so on.

My advice is to remove the padding, or set them to very small values. Then, make sure you use all of the geometry manager options that are available to you, such as fill and expand with pack, and sticky and others for grid.