New pack and grid Features

Asymmetric Padding

Both the pack and grid commands now support asymmetric padding. If you provide a single screen distance value to either -padx or -pady, then that value is used for both the left and right (or top and bottom) padding around the widget, just as it has been in previous versions of Tk. But now if you provide a 2-element list of screen distance values, then the first value determines the padding on the left (top), and the second value determines the padding on the right (bottom).

Uniform Rows and Columns in grid

The new -uniform option for grid columnconfigure and grid rowconfigure makes it easier to create layouts with equal-sized cells. (TIP #37)