def __init__(self, text=None, fn=None):
        # Literal playlist source content
        if text:
            self.src = text
        # Only read filename if it matches allowed extension
        if fn and self.probe_ext(fn):
            self.fn = fn
            self.src = open(fn, conf.open_mode).read()


    # Test URL/path "extension" for ".pls" / ".m3u" etc.
    def probe_ext(self, url):
        e = re.findall("\.(pls|m3u|xspf|jspf|asx|wpl|wsf|smil|html|url|json|desktop)\d?$", url)
        if e: return e[0]
        else: pass