def streams(self, stream_types=None, sorting_excludes=None):

        try:
            ostreams = self._get_streams()
            if isinstance(ostreams, dict):
                ostreams = ostreams.items()

            # Flatten the iterator to a list so we can reuse it.
            if ostreams:
                ostreams = list(ostreams)
        except NoStreamsError:
            return {}
        except (IOError, OSError, ValueError) as err:
            raise PluginError(err)

        if not ostreams:
            return {}

        if stream_types is None:
            stream_types = self.default_stream_types(ostreams)

        # Add streams depending on stream type and priorities
        sorted_streams = sorted(iterate_streams(ostreams),
                                key=partial(stream_type_priority,
                                            stream_types))

        streams = {}
        for name, stream in sorted_streams:
            stream_type = type(stream).shortname()

            if stream_type not in stream_types:
                continue

            existing = streams.get(name)
            if existing:
                existing_stream_type = type(existing).shortname()
                if existing_stream_type != stream_type:
                    name = "{0}_{1}".format(name, stream_type)

                if name in streams:
                    name = "{0}_alt".format(name)
                    num_alts = len(list(filter(lambda n: n.startswith(name), streams.keys())))

                    # We shouldn't need more than 2 alt streams
                    if num_alts >= 2:
                        continue
                    elif num_alts > 0:
                        name = "{0}{1}".format(name, num_alts + 1)

            # Validate stream name and discard the stream if it's bad.
            match = re.match("([A-z0-9_+]+)", name)
            if match:
                name = match.group(1)
            else:
                self.logger.debug("The stream '{0}' has been ignored "
                                  "since it is badly named.", name)
                continue

            # Force lowercase name and replace space with underscore.
            streams[name.lower()] = stream

        # Create the best/worst synonmys
        stream_weight_only = lambda s: (self.stream_weight(s)[0] or
                                        (len(streams) == 1 and 1))
        stream_names = filter(stream_weight_only, streams.keys())
        sorted_streams = sorted(stream_names, key=stream_weight_only)

        if isinstance(sorting_excludes, list):
            for expr in sorting_excludes:
                filter_func = stream_sorting_filter(expr, self.stream_weight)
                sorted_streams = list(filter(filter_func, sorted_streams))
        elif callable(sorting_excludes):
            sorted_streams = list(filter(sorting_excludes, sorted_streams))

        if len(sorted_streams) > 0:
            best = sorted_streams[-1]
            worst = sorted_streams[0]
            streams["best"] = streams[best]
            streams["worst"] = streams[worst]

        return streams
Attempts to extract available streams.
dataset/ETHPy150Open chrippa/livestreamer/src/livestreamer/plugin/plugin.py/Plugin.streams