用python替换bash脚本-检查进程是否正在运行？

Question

This is what I have currently (checks a number of processes, this is just one) and it works magically:

if role=Agent
then 
    echo "Validations for the service $servicename..."
        livefilterd=$(pgrep -f backgroundd)
            if [ -n "$livefilterd" ]
                    then
                            printf "The $servicename service is running as: \n$livefilterd"
                                let statusfilterd=1
                    else
                            echo -ne '!!!The $servicename process is NOT running!!!\r';sleep 0.5;echo -ne '   The $servicename process is NOT running   \r';sleep 0.5;echo -ne '!!!The $servicename process is NOT running!!!\r';sleep 0.5;echo -ne '   The $servicename process is NOT running   \r';sleep 0.5;
                                let "badkids=badkids+1"
                                let statusfilterd=0
            fi
else
    print "Validation for $servicename is being skipped as it's not expected on this host due to the role of $role."
fi

I'd like to move this to python, and most of the script I've been able to figure out and test, but I'm having issues with the block above. This is where I've gotten, but I'm not sure I can nest a try/except within an if/else statement, and would greatly appreciate some help:

servicename=backgroundd
if role == 'Agent': 
    print ("Validations for the service " + servicename + "...")
try:
    get_pid("backgroundd")    
    print ("YAY")
    print ("The " + servicename + " service is running as:" + servicename)
    statusfilterd = 1
except Exception:
    cprint("\n!!!!The " + servicename + " process is NOT running!!!!", 'red', attrs=['blink'])
    badkids = badkids+1
    statusfilterd = 0
else
    print ("Validation for $servicename is being skipped as it's not expected on this host due to the role of $role.")
print();print();time.sleep(0.5)

Where is my mistake within this??? Many thanks in advance!!

Answer 1

You can nest a try/except inside an if/else, but you will need to be careful of indentation, as that is how Python indicates blocks of code.

servicename=backgroundd
if role == 'Agent': 
    print ("Validations for the service " + servicename + "...")
    try:
        get_pid("backgroundd")    
        print ("YAY")
        print ("The " + servicename + " service is running as:" + servicename)
        statusfilterd = 1
    except Exception:
        cprint("\n!!!!The " + servicename + " process is NOT running!!!!", 'red', attrs=['blink'])
        badkids = badkids+1
        statusfilterd = 0
else:
    print ("Validation for $servicename is being skipped as it's not expected on this host due to the role of $role.")
print();print();time.sleep(0.5)