Clear memory cache from python

Question

I am using python because i try to run some queries from psql in cold state in a for loop.So before the execution of every query my cache must be clear! I imported os and then i did this:

if state=="cold":
         os.system('sudo sh -c "sync; echo 3 > /proc/sys/vm/drop_caches"')

I am getting this output:

sh: 1: cannot create /proc/sys/vm/drop_caches: Permission denied

sudo: a terminal is required to read the password; either use the -S option to read from standard input or configure an askpass helper

I dont know how to fix this.

sudo requires to enter the password manually. you cant enter from your code unless you use -S option. try -S option — alexzander, Mar 01 '21 at 10:50
and you get permission denied because you didnt enter password from sudo prompt and basically that wasnt sudo — alexzander, Mar 01 '21 at 10:50

score 1 · Accepted Answer · answered Mar 01 '21 at 10:58

acorrding to this stack question:

how to pass sudo password from python script

you can try this:

password = 'my sudo password'
command = 'sh -c "sync; echo 3 > /proc/sys/vm/drop_caches"'

# formatting the sudo password and the command
shell_script = f"echo {password} | sudo -S {command}"

# running the script
os.system(shell_script)

Clear memory cache from python

1 Answers1