Dima
Kolya
Vanya

import itertools 
for name, num in itertools.product(open('name.txt'), [1,2,3]):
    print(name,':', num)

Dima
 : 1

i = 1
for x in open("name.txt"):
	print x[:-1] +" : " + str(i)
	i += 1

import itertools
for name, num in itertools.product(open('name.txt'), [1,2,3]):
    print(name.rstrip() ,':', num)

>>> with open('t.txt', 'r') as f:
	nameList = f.readlines()

>>> outStr = '\n'.join(['%s : %s'%(nameList[i].rstrip() , i+1) for i in xrange(len(nameList))])
>>> print outStr
Dima : 1
Kolya : 2
Vanya : 3
Vanya : 4
Dima : 5
Kolya : 6
Vanya : 7
name_number_123054 : 8