OS command via python subprocess module

[Gribouillis]

Seems like now unzip is not working and hence chdir too.

Then you need to determine if unzip failed or not. It seems very likely to me that you'd get an error message if unzip failed. I don't know the contents of the zip file. Don'tyou have a typo in the new directory name? (such as a missing 'p' for example). You could list the directory before and after unzipping in order to see the changes. You could also pass the -v switch to unzip to get verbose output. Do

print(cmd.unzip('-o', '-v', "/u03/p{}_*.zip".format(i)))