error when using Pmw.BLT

[Robert Kern]

On 2009-10-21 10:50 AM, Yang Yang wrote:
> Hello,
>
> I tried to follow the following code demonstrating the use of Pmw.BLT:
>
>  >>> from Tkinter import *
>  >>> import Pmw
>  >>> master = Tk()
>  >>> g = Pmw.Blt.Graph( master )
>
> I got the following error message after I typed the last line:
>
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
>   File "C:\Python26\lib\site-
> packages\Pmw\Pmw_1_3\lib\PmwBlt.py", line
> 260, in _
> _init__
>     Tkinter.Widget.__init__(self, master, _graphCommand, cnf, kw)
>   File "C:\Python26\lib\lib-tk\Tkinter.py", line 1932, in __init__
>     (widgetName, self._w) + extra + self._options(cnf))
> _tkinter.TclError: invalid command name "::blt::graph
>
>
> I am a newbie in python. Does anybody know what causes this error? I
> am running python 2.6.3 under windows xp.

You need to install BLT for Tcl. It is not a standard part of Tcl, and it is not 
included in the version of Tcl that comes bundled with Python.

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco