I am using Python

I have the following columns, each row shows an "interaction" $-$

i$.$e$.$ when a device of type u is near a device of type a:

u$\_$imei $($device id of type u$),$

a$\_$imei $($device id of type a$),$

u$\_$ping$\_$time $($timestamp of device of type u$),$

a$\_$ping$\_$time $($timestamp of device of type a$),$

u$\_$ping$\_$id $($unique ping id of type u$),$

a$\_$ping$\_$id $($unique ping id of type a$)$

Please note each device sends one ping per minute.

For each unique combination of u$\_$imei, a$\_$imei, I want to calculate the duration of an interaction as follows:

if the next row is $2$ minutes or less apart, then merge the duration and consider it part of the same interaction.

if the next row is $3$ minutes or more apart, then consider that as a seperate interaction.

i want start and end time and duration of each such unique interaction.