[python-win32] Writing to Excel performance

[Tim Golden]

Dominick Lauzon wrote:

> I have large matrices of data to push to excel and I find the writing of
> data to excel to be excessively slow (cell by cell method) even if the
> Visible is to False.

> 
> Right now I reverted back to a 2 step CSV - Import to Excel but it is
> far from ideal.

> 
> Is there any trick to accumulate the data and push it to Excel all at
> once or any other way to improve performance altogether ?


Using COM (which I assume you are from the reference to Visible)
you can add a range at a time as a Python list or list of lists:

<code>
import win32com.client

xl = win32com.client.gencache.EnsureDispatch ("Excel.Application")
xl.Visible = True
sheet = xl.Workbooks.Add ().ActiveSheet
sheet.Range (sheet.Cells (1, 1), sheet.Cells (10, 10)).Value = \
  [range (10) for i in range (10)]

</code>


I suspect -- tho' I've never tried to find out -- that using something
like xlwt (and when I say "something like xlwt" I really mean "xlwt")
might be faster since it doesn't have to manipulate the interface at the
same time:

http://pypi.python.org/pypi/xlwt


Lastly there is a Google Group set up for Python-Excel issues and
you might want to lurk or ask there:

http://groups.google.com.au/group/python-excel

TJG