[Tkinter] how to get the size of a column or a row of grid manager?

[Jeff Epler]

I don't believe it's possible directly.  However, the Tk manpage for grid
mentions this:
       grid location master x y
              Given  x and y values in screen units  relative  to  the  master
              window,  the  column  and row number at that x and y location is
              returned.  For locations that are above or to the  left  of  the
              grid, -1 is returned.
This is exposed as the method .grid_location(x,y).  You could write
a method to return the width or height of a desired cell in terms of
this function.

Of course, for any widget contained in a row or column, you can use
.winfo_width()/.winfo_height() to find out how much space it's actually
using.  (If sticky includes "ns", then the height is the same as the
height of that cell, and if sticky includes "ew", then the width is the
same as the width of that cell)

And you can use .grid_{row,column}configure to set the relative weights
of rows that expand when the user resizes the screen.

Jeff