the open function in parse_files should include encoding type

[CoderHuo]

eg:

def parse_files(filenames,encoding=None):
    """Parse given ASN.1 specification file(s) and return a dictionary of
    its/their contents.

    >>> foo = asn1tools.parse_files('foo.asn')

    """

    if isinstance(filenames, str):
        filenames = [filenames]

    string = ''

    for filename in filenames:
        with open(filename, 'r',encoding=encoding) as fin:
            string += fin.read()
            string += '\n'

    return parse_string(string)

[eerimoq]

You should create a pull request, tested with both Python 2 and 3.

open() in Python 2 does not take the encoding argument. open() in the io-module takes the extra argument, but it reads unicode instead of str, which may be what we want, but in the cantools package I ended up opening the file differently in Python 2 and 3. See: https://github.com/eerimoq/cantools/blob/master/cantools/db/__init__.py#L65-L70

[CoderHuo]

Thank you very much.