TIFF to PDF

[revuesbio]

I'm trying to use tifflib but i have some problems.
When i use direct command line like
"C:\Program Files\GnuWin32\bin\tiff2pdf.exe" -o C:\test.pdf C:
\test.TIF
the pdf file is ok.

but when i try to launch command line via python the pdf file doesn't
create.

import os
os.system('"C:\Program Files\GnuWin32\bin\tiff2pdf.exe" -o C:\test.pdf
C:\test.TIF')

where is the problem ?