unix wc | tail commands in python

wc-tail.py

def wc (fname, options = "-l"):
    p = subprocess.Popen(['wc', options, fname], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    result, err = p.communicate()
    if p.returncode != 0:
        return -1
    return int(result.strip().split()[0])


def tail (fname, n = 30, out = subprocess.PIPE):
    p = subprocess.Popen(['tail', '-n', str(n), fname], stdout=out, stderr=subprocess.PIPE)
    result, err = p.communicate()
    if p.returncode != 0:
        return -1
    return n
    
    
wc = wc("test.txt")
n = wc - 10
if n > 0:
    with open("test-tail.txt", "w") as f:
        tail("test.txt", n, f)
        print "\ttail -n %d %s > %s" % (n, "test.txt", f.name)