VCF Filtration doesn't work with uncompressed, or UTF-8

[OgnjenMilicevic]

Hi!

I tried applying your filtering script on an uncompressed VCF, and it returns an error:
TypeError: startswith first arg must be bytes or a tuple of bytes, not str

It works when I gzip the file, but it fails on an UTF-8 character.

I see some fixed but the vcf_filter has not been changed for 6 years, any chance we can get an update on it to handle these two issues?

[OgnjenMilicevic]

The core of the first problem seems to be that you are parsing the input with the binary opener long before you pass it to reader and assign it a reader:

parser.add_argument('input', metavar='input', type=argparse.FileType('rb'), nargs='?', default=None,
        help='File to process (use - for STDIN)')