from py.magic import greenlet
import xml.parsers.expat


# ____________________________________________________________

def send(arg):
    greenlet.getcurrent().parent.switch(arg)

# 3 handler functions
def start_element(name, attrs):
    send(('start', name, attrs))
def end_element(name):
    send(('end', name))
def char_data(data):
    data = data.strip()
    if data:
        send(('data', data))

def greenparse(*args):
    p = xml.parsers.expat.ParserCreate()
    p.StartElementHandler = start_element
    p.EndElementHandler = end_element
    p.CharacterDataHandler = char_data
    p.Parse(*args)

def iterparse(*args):
    g = greenlet(greenparse)
    data = g.switch(*args)
    while data is not None:
        yield data
        data = g.switch()

# ____________________________________________________________

EXAMPLE = '''<?xml version="1.0"?>
                 <parent id="top">
                     <child1 name="paul">
                         Text goes here
                     </child1>
                     <child2 name="fred">
                        More text
                     </child2>
                 </parent>'''

for data in iterparse(EXAMPLE, 1):
    print data