Programming Python, Second Edition

Grids

So far, we’ve been arranging widgets in displays by calling their pack methods -- an interface to the packer geometry manager in Tkinter. This section introduces grid, the most commonly used alternative to the packer.

As we learned earlier, Tkinter geometry managers work by arranging child widgets within a parent container widget (parents are typically Frames or top-level windows). When we ask a widget to pack or grid itself, we’re really asking its parent to place it among its siblings. With pack, we provide constraints and let the geometry manager lay out widgets appropriately. With grid, we arrange widgets in rows and columns in their parent, as though the parent container widget was a table.

Gridding is an entirely distinct geometry management system in Tkinter. In fact, at this writing pack and grid are mutually exclusive for widgets that have the same parent -- within a given parent container, we can either pack widgets or grid them, but not both. That makes sense, if you realize that geometry managers do their jobs at parents, and a widget can only be arranged by one geometry manager.

At least within one container, though, that means that you must pick either grid or pack and stick with it. So why grid, then? In general, grid is handy for laying out form-like displays; arranging input fields in row/column fashion can be at least as easy as laying out the display with nested frames. As we’ll see, though, grid doesn’t offer substantial code or complexity savings ...