How to pass variable in mysql query Trying to fetch latitude and longitude

Question

long='73.9876'

lati='18.6543'

query="SELECT user_id ,SQRT(POW(69.1 * (latitude - lati), 2) + POW(69.1 * (longi - longitude) * COS(latitude / 57.3), 2)) AS distance from users HAVING distance < 30 ORDER BY distance where latitude=%s AND longitude=%s"

#### value of lati and longi will be user defined, how I will make it dynamic. please help me to resolve this problem. thanks in advance.