sequential id for each class which contain couple of hundred of points.

hello python hero and legends.
i have more then 23 routes generated by using network analyst. later on, i have converted the route into point shapefile. new formed point shapefile have many hundred of points for each routes. i have created a new column and i want to populate that column with sequential numbers for each point. a python script is available for such calculation but this scripts generates sequential number starting from 1st point to last one regardless the route class. i am looking for some advance calculation. i want sequential numbering for each route in new column. like
route type seq.no
1 point 1
1 point 2
1 point 3
1 point 4
2 point 1
2 point 2
2 point 3
.
.
.
.
so on.
i need all this is a single python script.
looking forward your great contribution.

Nadeem Fareed