pythonic way to iterate over part of a list

You can try itertools.islice(iterable[, start], stop[, step]):

import itertools
for line in itertools.islice(list , start, stop):
     foo(line)

The original solution is, in most cases, the appropriate one.

for line in lines[2:]:
    foo(line)

While this does copy the list, it is only a shallow copy, and is quite quick. Don't worry about optimizing until you have profiled the code and found this to be a bottleneck.

Although itertools.islice appears to be the optimal solution for this problem, somehow, the extra import just seems like overkill for something so simple.

Personally, I find the enumerate solution perfectly readable and succinct - although I would prefer to write it like this:

for index, line in enumerate(lines):
    if index >= 2:
        foo(line)

You might build a helper generator:

def rangeit(lst, rng):
  for i in rng:
    yield lst[i]

for e in rangeit(["A","B","C","D","E","F"], range(2,4)):
  print(e)