TIFF to PDF

[revuesbio]

I'm trying to use tifflib but i have some problems :

when i use direct command line :
"C:\Program Files\GnuWin32\bin\tiff2pdf.exe" -o C:\test.pdf C:
\test.TIF

the pdf is ok.

but when i try to launch command line via python the pdf file is not
created.
where is the problem ?
import os
os.system('"C:\Program Files\GnuWin32\bin\tiff2pdf.exe" -o C:\test.pdf
C:\test.TIF')

thank you