def func_split(stream_stream, arg_from=None):
before = copyStream(stream_stream)
after = copyStream(stream_stream)
arg_from -= 1
channel = before.find("channel")
items = before.findall("channel/item")
for item in items[arg_from:]:
channel.remove(item)
channel = after.find("channel")
items = after.findall("channel/item")
for item in items[:arg_from]:
channel.remove(item)
return before, after
def func_join(stream_first, stream_second):
result = copyStream(stream_first)
channel = result.find("channel")
for item in stream_second.findall("channel/item"):
channel.append(item)
return result
