Functional head & tail in Python

head_n_tail.py

from itertools import islice
from toolz.itertoolz import sliding_window, last
import codecs
import os

def head(path, n=10, encoding="utf-8"):
    with codecs.open(os.path.expanduser(path), encoding=encoding) as f:
        yield from map(lambda x: x.rstrip(), islice(f, n))

def tail(path, n=10, encoding="utf-8"):
    with codecs.open(os.path.expanduser(path), encoding=encoding) as f:
        lines = last(sliding_window(n, f))
        yield from map(lambda x: x.rstrip(), lines)