Setting an Excel Range with an Array using Python and comtypes?

Question

Using comtypes to drive Python, it seems some magic is happening behind the scenes that is not converting tuples and lists to VARIANT types:

# RANGE(“C14:D21”) has values
# Setting the Value on the Range with a Variant should work, but
# list or tuple is not getting converted properly it seems

>>>from comtypes.client import CreateObject
>>>xl = CreateObject("Excel.application")
>>>xl.Workbooks.Open(r'C:\temp\my_file.xlsx')
>>>xl.Visible = True
>>>vals=tuple([(x,y) for x,y in zip('abcdefgh',xrange(8))])
# creates: 
#(('a', 0), ('b', 1), ('c', 2), ('d', 3), ('e', 4), ('f', 5), ('g', 6), ('h', 7))
>>>sheet = xl.Workbooks[1].Sheets["Sheet1"]
>>>sheet.Range["C14","D21"].Value()
(('foo',1),('foo',2),('foo',3),('foo',4),('foo',6),('foo',6),('foo',7),('foo',8))
>>>sheet.Range["C14","D21"].Value[()] = vals
# no error, this blanks out the cells in the Range

According to the comtypes docs:

When you pass simple sequences (lists or tuples) as VARIANT parameters, the COM server will receive a VARIANT containing a SAFEARRAY of VARIANTs with the typecode VT_ARRAY | VT_VARIANT.

This seems to be inline with what MSDN says about passing an array to a Range's Value. I also found this page showing something similar in C#. Can anybody tell me what I'm doing wrong?

EDIT

I've come up with a simpler example that performs the same way (in that, it does not work):

>>>from comtypes.client import CreateObject
>>>xl = CreateObject("Excel.application")
>>>xl.Workbooks.Add()
>>>sheet = xl.Workbooks[1].Sheets["Sheet1"]
# at this point, I manually typed into the range A1:B3
>>> sheet.Range("A1","B3").Value()
((u'AAA', 1.0), (u'BBB', 2.0), (u'CCC', 3.0))
>>>sheet.Range("A1","B3").Value[()] = [(x,y) for x,y in zip('xyz',xrange(3))]
# Using a generator expression, per @Mike's comment
# However, this still blanks out my range :(

Answer 1

Try sheet.Range("C14", "D21").Value = vals. I'm not quite sure how the API is structured, but it works for me.

(Also, tuple([(x,y) for x,y in zip('abcdefgh',xrange(8))]) can be replaced with a generator expression tuple((x, y) for x, y in zip('abcdefgh', xrange(8))), which is seems a bit cleaner habit to have. In this particular case, just the list comprehension [(x, y) for x, y in zip('abcdefgh', xrange(8))] would also do.)