win32com ChartObject pythonwin vs idle

sterling sterlingsomers at
Thu Jul 31 17:13:32 CEST 2008

On Jul 31, 4:28 am, Tim Golden <m... at> wrote:
> sterling wrote:
> > I'm curious as to why the difference between IDLE and pythonWin when
> > using win32com.
> > opening an excel file, i've attempted to grab the chart information
> > out of the file.
> > commands like co = ChartObjects(1)  works in pythonWin but doesn't
> > work in IDLE.
> > however, on both co = chartobjects(1) works just fine.
> I can't speak for IDLE vs PythonWin but in general
> case-sensitivity of win32com stuff is related to
> early vs late Dispatch. If you've explicitly generated
> proxy modules for the Excel objects (via makepy,
> EnsureDispatch or whatever) then those are Python
> modules with case-sensitivity. If you're using dynamic
> dispatch then Python is simply passing your attribute
> name along to COM, which isn't case-sensitive, so either
> case will work.
> Not sure why IDLE vs PythonWin should make a difference
> here, but maybe the above explanation sheds some light...

Thanks Tim.  I'm wondering if it's an OS issues with Vista (I'm
strangly ashamed to admit that both my laptop and main computer are
running it).
I decided to try the same code on my main computer (do most of my work
on my laptop) and the exact same thing has happened: I can run it in
pythonwin and not idle.
I found that I can't even run Open (I must have been running open()
>>> import win32com.client
>>> ex = win32com.client.Dispatch("Excel.Application")
>>> wb = ex.Workbooks.Open("C:\Temp\SalesChart.xls")

Traceback (most recent call last):
  File "<pyshell#2>", line 1, in <module>
    wb = ex.Workbooks.Open("C:\Temp\SalesChart.xlsx")
  File "C:\Python25\Lib\site-packages\win32com\client\",
line 467, in __getattr__
    if self._olerepr_.mapFuncs.has_key(attr): return
  File "C:\Python25\Lib\site-packages\win32com\client\",
line 295, in _make_method_
    methodCodeList =
  File "C:\Python25\Lib\site-packages\win32com\client\", line
297, in MakeFuncMethod
    return self.MakeDispatchFuncMethod(entry, name, bMakeClass)
  File "C:\Python25\Lib\site-packages\win32com\client\", line
318, in MakeDispatchFuncMethod
    s = linePrefix + 'def ' + name + '(self' + BuildCallList(fdesc,
names, defNamedOptArg, defNamedNotOptArg, defUnnamedArg, defOutArg) +
  File "C:\Python25\Lib\site-packages\win32com\client\", line
604, in BuildCallList
    argName = MakePublicAttributeName(argName)
  File "C:\Python25\Lib\site-packages\win32com\client\", line
542, in MakePublicAttributeName
    return filter( lambda char: char in valid_identifier_chars,
  File "C:\Python25\Lib\site-packages\win32com\client\", line
542, in <lambda>
    return filter( lambda char: char in valid_identifier_chars,
UnicodeDecodeError: 'ascii' codec can't decode byte 0x83 in position
52: ordinal not in range(128)

but the exact same code works in PythonWin. Perhaps I will just find a
way to code everything I want in the older lowercase.

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