PyWart: The problem with "print"

[Rick Johnson]

On Monday, June 3, 2013 10:16:13 PM UTC-5, Vito De Tullio wrote:
> Rick Johnson wrote:
> > Take your
> > standard yes/no/cancel dialog, i would expect it to return
> > True|False|None respectively,
> you clearly mean True / False / FileNotFound.

No, i clearly meant what i said :-). FileDialogs only return
one of two values; either a valid path or a value
representing "failure". I suppose FileNotFound is a custom
exception? That will work however i wonder if exception
handling is overkill for this?

  try:
      path = filedialog.open("path")
  except FileNotFound:
      return
  do_something(path)

As opposed to:

  path = filedialog.open("path")
  if path:
      do_something(path)

Or, if Python was really cool!

  if filedialog.open("path") as path:
      do_something(path)

However, i think True|False|None is the best return values
for a yes|no|cancel choice. Consider:

  result = yesnocancel("save changes?")
  if result:
      # Try to save changes and close.
      if self.fileSave():
          app.close()
      else:
          show_error()
  elif result is False:
      # Close without saving changes.
      app.close()
  else:
      # Canceled: Do nothing.
      return