I tried to merge the two "tk configure command"s explanation from tk widget and ttk widget into one easy explanation with description of the list’s format instead of Tk_ConfigureInfo which I found difficult to work with :
pathName configure ?option? ?value option value ...?
Query or modify the configuration options of the widget.
If no option is specified, returns a list describing all of the available options for pathName: the elements of the list are the option name, database name, database class, default value, and current value.
If option is specified with no value, then the command returns a list describing the one named option (this list will be identical to the corresponding sublist of the value returned if no option is specified).
If one or more option-value pairs are specified, then the command modifies the given widget option(s) to have the given value(s); in this case the command returns an empty string. Option may have any of the values accepted by the Widget command.