Application window geometry specifier

[Chris Angelico]

On Wed, Jan 13, 2021 at 3:38 AM Rich Shepard <rshepard at appl-ecosys.com> wrote:
>
> I want my application's window (main frame) to open centered on the
> monitor's screen. This code:
>         # open application centered on screen; set window width and height
>          self.appwidth = 600
>          self.appheight = 500
>          # get screen width and height
>          self.scrwidth = self.winfo_screenwidth()
>          self.scrheight = self.winfo_screenheight()
>          # formula to find screen center
>          self.xLeft = (self.scrwidth/2) - (self.appwidth/2)
>          self.yTop = (self.scrheight/2) - (self.appheight/2)
>          # set geometry
>          self.geometry(str(self.appwidth) + "x" + str(self.appheight) +
>                        "+" + str(self.xLeft) + "+" + str(self.yTop))
>
> generates this error when run:
>   File "/usr/lib64/python3.9/tkinter/__init__.py", line 2036, in wm_geometry
>      return self.tk.call('wm', 'geometry', self._w, newGeometry)
> _tkinter.TclError: bad geometry specifier "600x500+340.0+262.0"
>
> As the geometry string represents window width times window height plus x-offset
> plus y-offset I'm not seeing my error.
>

Do the offsets need to be integers?

ChrisA