file_progress.py

from os.path import getsize
from progressbar import ProgressBar

class ProgOpen(object):
    def __init__(self, filename):
        self.filename = filename

    def __iter__(self):
        return self

    def __enter__(self, *params):
        size = getsize(self.filename)
        self.fh = open(self.filename)
        self.progbar = ProgressBar(maxval=size).start()
        return self

    def __exit__(self, *params):
        print
        self.fh.close()

    def next(self):
        self.progbar.update(self.fh.tell())
        rn = self.fh.next()
        return rn