corpus.py 文件源码

def remove_line(fname, line):
    '''Remove line from file by creating a temporary file containing all lines
    from original file except those matching the given line, then copying the
    temporary file back into the original file, overwriting its contents.
    '''
    with lockfile.FileLock(fname):
        tmp = tempfile.TemporaryFile()
        fp = open(fname, 'rw+')
        # write all lines from orig file, except if matches given line
        for l in fp:
            if l.strip() != line:
                tmp.write(l)

        # reset file pointers so entire files are copied
        fp.seek(0)
        tmp.seek(0)
        # copy tmp into fp, then truncate to remove trailing line(s)
        shutil.copyfileobj(tmp, fp)
        fp.truncate()
        fp.close()
        tmp.close()