[python-win32] win32com- Type mismatch on a string... Possible hash key collision?

[Reedick, Andrew]

I'm converting working Perl COM scripts to Python (ActivePython
2.5.1.1)and I've hit an odd situation where win32com throws a 'Type
mismatch' error on a string.

It's odd because a) it works in ActiveState Perl, b) other methods in
the object work just fine in Python, and c) it looks suspiciously like a
key collision in an internal hash.

The following method works successfully:
	a = self.tdc.Customization.Fields.Field("REQ", "RQ_REQ_ID")
	print a.ColumnName

but the following fails:
	b = self.tdc.Customization.Fields.Fields("BUG")

I think the problem is "...Fields.Fields(...)"  The two Fields objects
are different objects but happen to have the same name.  (The 1st Fields
is a CustomizationFields object, and the 2nd Fields is TDField object
with different properties and different methods.)


I have extra debugging turned on in
Python25\lib\site-packages\win32com\client\dynamic.py.  Here's the
debugging with notes and the traceback:

	TDApiOle80.TDConnection.__LazyMap__(InitConnectionEx) added
something
	TDApiOle80.TDConnection.__LazyMap__(Login) added something
	TDApiOle80.TDConnection.__LazyMap__(Connect) added something
	TDApiOle80.TDConnection.__LazyMap__(ProjectConnected) added
something

	Attribute ProjectConnected not in cache
	Getting property Id 0x2 from OLE object
	OLE returned  True
	TDApiOle80.TDConnection.__LazyMap__(Customization) added
something

	Attribute Customization not in cache
	Getting property Id 0x1a from OLE object
	OLE returned  <PyIDispatch at 0xb409b4 with obj at 0xdbfebc>
	<unknown>.__LazyMap__(Fields) added something

a = self.tdc.Customization.Fields.Field("REQ", "RQ_REQ_ID")

self.tdc.Customization.Fields.Field
	Attribute Fields not in cache
	Getting property Id 0x6 from OLE object
	OLE returned  <PyIDispatch at 0xa4692c with obj at 0xdb39a4>
	<unknown>.__LazyMap__(Field) added something

print a.ColumnName
	Field.__LazyMap__(ColumnName) added something
	Attribute ColumnName not in cache
	Getting property Id 0x13 from OLE object
	OLE returned  RQ_REQ_ID
	RQ_REQ_ID


b = self.tdc.Customization.Fields.Fields("BUG")

	Attribute Customization not in cache
	Getting property Id 0x1a from OLE object
	OLE returned  <PyIDispatch at 0xabaa34 with obj at 0xdbfebc>
	<unknown>.__LazyMap__(Fields) added something

self.tdc.Customization.Fields
	Attribute Fields not in cache
	Getting property Id 0x6 from OLE object
	OLE returned  <PyIDispatch at 0xac0a54 with obj at 0xdb39a4>
	<unknown>.__LazyMap__(Fields) added something

self.tdc.Customization.Fields.Fields
	Attribute Fields not in cache
	Getting property Id 0x2 from OLE object
	OLE returned  <PyIDispatch at 0xae22b4 with obj at 0x18b7270>

boom	Traceback (most recent call last):
	  File "TDC.py", line 112, in <module>
	    tdc.MapUserFields2DatabaseFields('BUG')
	  File "TDC.py", line 61, in MapUserFields2DatabaseFields
	    b = self.tdc.Customization.Fields.Fields("BUG")
	  File
"c:\Python25\lib\site-packages\win32com\client\dynamic.py", line 172, in
	__call__
	    return
self._get_good_object_(self._oleobj_.Invoke(*allArgs),self._olerepr_.
	defaultDispatchName,None)
	pywintypes.com_error: (-2147352571, 'Type mismatch.', None, 1)


How the heck do you get a Type Mismatch on a string?

Again, the ...Fields.Field("TableName", "FieldName") method works just
fine, but ...Fields.Fields("TableName") method fails miserably.  



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