Open the SDK from the URL, which can be either a network location or
    a filename path. Returns a file-like object open for reading.

def open_sdk(url):
    """Open the SDK from the URL, which can be either a network location or
    a filename path. Returns a file-like object open for reading.
    """
    if urlparse.urlparse(url).scheme:
        return _download(url)
    else:
        return open(url)