Empty condition for Result Set in Python Client

I have stored data about vehicles by storing there vehicle numbers as tags.

Now, I want to get those vehicle numbers which have not been updated in recent time(recent 2 days).
For that, I query data from influxdb, and if result set is empty, means it has not been updated.

What condition statement should I use for empty result set ? Empty result set is given below.

 > result2 = c.query('SELECT "vehicleno", "tracktime" FROM "vehicleinfo" WHERE "vehicleno" =~ /^KA-03-AD-6629$/ AND time > now() - 48h') 
 > result2
 ResultSet({})

@Luv That looks right. I would suggest using the exact matcher on the where clause (WHERE "vehicleno" = 'KA-03-AD-6629') as it is more performant. What is the problem with that query?

@Luv, check the len of your results. If < 1 you should have your answer.