begin with the previous version' additions in the third editionpyedit was enhanced witha simple font specification dialog unlimited undo and redo of editing operations file modified tests whenever content might be erased or changed user configurations module here are some quick notes about these extensions font dialog for the third edition of the bookpyedit grew font input dialog-- simplethree-entrynonmodal dialog where you can type the font familysizeand styleinstead of picking them from list of preset options though functionalyou can find more sophisticated tkinter font selection dialogs in both the public domain and within the implementation of python' standard idle development gui (as mentioned earlierit is itself pythontkinter programundoredoand modified tests also new in the third editionpyedit supports unlimited edit undo and redoas well as an accurate modified check before quitopenrunand new actions to prompt for saves it now verifies exits or overwrites only if text has been changedinstead of always asking naively the underlying tk (or laterlibrary provides an apiwhich makes both these enhancements simple--tk keeps undo and redo stacks automatically they are enabled with the text widget' undo configuration option and are accessed with the widget methods edit_undo and edit_redo similarlyedit_reset clears the stacks ( after new file open)and edit_modified checks or sets the automatic text modified flag it' also possible to undo cuts and pastes right after you've done them (simply paste back from the clipboard or cut the pasted and selected text)but the new undo/redo operations are more complete and simpler to use undo was suggested exercise in the second edition of this bookbut it has been made almost trivial by the new tk api configuration module for usabilitythe third edition' version of pyedit also allows users to set startup configuration options by assigning variables in moduletextconfig py if present on the module search path when pyedit is imported or runthese assignments give initial values for fontcolorstext window sizeand search case sensitivity fonts and colors can be changed interactively in the menus and windows can be freely resizedso this is largely just convenience also note that this module' settings will be inherited by all instances of pyedit if it is importable in the client program--even when it is popup window or an embedded component of another application client applications pyedita text editor program/object