find your scsi controller (one of the /dev/sgX devices, perhaps using lsscsi)
change /dev/sgX in fanspeed.py if needed.
# python fan.py 2
Fan 0 speed: 0
Fan 1 speed: 947
Fan 2 speed: 932
Fan 3 speed: 812
Fan 4 speed: 932
Fan 5 speed: 947
Reading current configuration...
Setting fan 0 to 2
Setting fan 1 to 2
Setting fan 2 to 2
Setting fan 3 to 2
Setting fan 4 to 2
Setting fan 5 to 2
LENOVO ThinkServerSA120 1007
Sending Enclosure Control [0x2] page, with page length=296 bytes
Fan 0 speed: 0
Fan 1 speed: 945
Fan 2 speed: 932
Fan 3 speed: 812
Fan 4 speed: 926
Fan 5 speed: 945