Reading a text file

[gruntfutuk]

How about: (using Python 3)

from itertools import islice
with open(file_name) as fd:
    alternatelines = islice(fd, 0, None, 2)
    for line in alternatelines:
        print(len(line.rstrip()))

Same principle as above, but uses islice from itertools to step through the file by 2 lines at a time. (I used rstrip on assumption that each line has a newline character at the end.)