displaying version on help command

[schettino72]

Now that commands can be plugged-in later, it would be better to make doc_description a method so as to be possible to override.

Just check cmd-graphx:line291. The version-discovery to be imprinted in the help-msg runs at import-time.

doc_description is used by doit help system as an attribute of Command instance (accessed as self.doc_description as opposed to MyCommand.doc_description ). That means it is possible to overwrite it with a method decorated as a @property. Since it hardly makes sense to have dynamic content on the description it is usually defined at class level with a static string.

For this specific case where the "dynamic" part is the version of the command I suggest we add a new version attribute member to command and let the help system assemble different parts of the help message as it already do with doc_purpose, doc_usage, doc_description. This way there would be no need for a method just to create doc_description.