import web

urls = ("/.*", "hello")
app = web.application(urls, globals())

class hello:
  def GET(self):
    return 'Hello, world!'

if __name__ == "__main__":
  app.run()

def run(self, *middleware):
  return wsgi.runwsgi(self.wsgifunc(*middleware))

import web

class hello:
  def GET(self):
    return 'Hello, world!'

urls = ("/.*", "hello")
app = web.application(urls, globals())
application = app.wsgifunc()

app = web.application(urls, globals())
application = app.wsgifunc()

class application:
  def __init__(self, mapping=(), fvars={}, autoreload=None):
    if autoreload is None:
      autoreload = web.config.get('debug', False)
    self.init_mapping(mapping)
    self.fvars = fvars
    self.processors = []

    self.add_processor(loadhook(self._load))
    self.add_processor(unloadhook(self._unload))

    if autoreload:
      ...

def init_mapping(self, mapping):
  self.mapping = list(utils.group(mapping, 2))

urls = ("/", "Index",
    "/hello/(.*)", "Hello",
    "/world", "World")

self.mapping = [["/", "Index"],
        ["/hello/(.*)", "Hello"],
        ["/world", "World"]]

  self.add_processor(loadhook(self._load))
  self.add_processor(unloadhook(self._unload))

def session_hook():
  web.ctx.session = session

app.add_processor(web.loadhook(session_hook))

def wsgifunc(self, *middleware):
  """Returns a WSGI-compatible function for this application."""
  ...
  for m in middleware: 
    wsgi = m(wsgi)

  return wsgi

def wsgi(env, start_resp):
  # clear threadlocal to avoid inteference of previous requests
  self._cleanup()

  self.load(env)
  try:
    # allow uppercase methods only
    if web.ctx.method.upper() != web.ctx.method:
      raise web.nomethod()

    result = self.handle_with_processors()
    if is_generator(result):
      result = peep(result)
    else:
      result = [result]
  except web.HTTPError, e:
    result = [e.data]

  result = web.safestr(iter(result))

  status, headers = web.ctx.status, web.ctx.headers
  start_resp(status, headers)

  def cleanup():
    self._cleanup()
    yield '' # force this function to be a generator

  return itertools.chain(result, cleanup())

for m in middleware: 
  wsgi = m(wsgi)

return wsgi

  self._cleanup()
  self.load(env)

  try:
    # allow uppercase methods only
    if web.ctx.method.upper() != web.ctx.method:
      raise web.nomethod()

    result = self.handle_with_processors()
    if is_generator(result):
      result = peep(result)
    else:
      result = [result]
  except web.HTTPError, e:
    result = [e.data]

  result = web.safestr(iter(result))

  status, headers = web.ctx.status, web.ctx.headers
  start_resp(status, headers)

  def cleanup():
    self._cleanup()
    yield '' # force this function to be a generator

  return itertools.chain(result, cleanup())

def loadhook(h):
  def processor(handler):
    h()
    return handler()

  return processor

def unloadhook(h):
  def processor(handler):
    try:
      result = handler()
      is_generator = result and hasattr(result, 'next')
    except:
      # run the hook even when handler raises some exception
      h()
      raise

    if is_generator:
      return wrap(result)
    else:
      h()
      return result

  def wrap(result):
    def next():
      try:
        return result.next()
      except:
        # call the hook at the and of iterator
        h()
        raise

    result = iter(result)
    while True:
      yield next()

  return processor

def handle_with_processors(self):
  def process(processors):
    try:
      if processors:
        p, processors = processors[0], processors[1:]
        return p(lambda: process(processors))
      else:
        return self.handle()
    except web.HTTPError:
      raise
    except (KeyboardInterrupt, SystemExit):
      raise
    except:
      print >> web.debug, traceback.format_exc()
      raise self.internalerror()

  # processors must be applied in the resvere order. (??)
  return process(self.processors)

  self.add_processor(loadhook(self._load))
  self.add_processor(unloadhook(self._unload))

self.processors = [loadhook(self._load), unloadhook(self._unload)]

self.processors = [load_processor, unload_processor]

def handle_with_processors(self):
  def process(processors):
    try:
      if processors: # 位置2
        p, processors = processors[0], processors[1:]
        return p(lambda: process(processors)) # 位置3
      else:
        return self.handle() # 位置4
    except web.HTTPError:
      raise
    ...

  # processors must be applied in the resvere order. (??)
  return process(self.processors) # 位置1

self.processors = [load_processor, unload_processor]

return load_processor(lambda: process([unload_processor]))

def load_processor(lambda: process([unload_processor])):
  self._load()
  return process([unload_processor]) # 就是参数的lambda函数

return unload_processor(lambda: process([]))

def unload_processor(lambda: process([])):
  try:
    result = process([]) # 参数传递进来的lambda函数
    is_generator = result and hasattr(result, 'next')
  except:
    # run the hook even when handler raises some exception
    self._unload()
    raise

  if is_generator:
    return wrap(result)
  else:
    self._unload()
    return result

  self._load()
    self.handle()
  self._unload()

def handle(self):
  fn, args = self._match(self.mapping, web.ctx.path)
  return self._delegate(fn, self.fvars, args)

def _match(self, mapping, value):
  for pat, what in mapping:
    if isinstance(what, application): # 位置1
      if value.startswith(pat):
        f = lambda: self._delegate_sub_application(pat, what)
        return f, None
      else:
        continue
    elif isinstance(what, basestring): # 位置2
      what, result = utils.re_subm('^' + pat + '$', what, value)
    else: # 位置3
      result = utils.re_compile('^' + pat + '$').match(value)

    if result: # it's a match
      return what, [x for x in result.groups()]
  return None, None

fn, args = self._match(self.mapping, web.ctx.path)
return self._delegate(fn, self.fvars, args)

def _delegate(self, f, fvars, args=[]):
  def handle_class(cls):
    meth = web.ctx.method
    if meth == 'HEAD' and not hasattr(cls, meth):
      meth = 'GET'
    if not hasattr(cls, meth):
      raise web.nomethod(cls)
    tocall = getattr(cls(), meth)
    return tocall(*args)

  def is_class(o): return isinstance(o, (types.ClassType, type))

  if f is None:
    raise web.notfound()
  elif isinstance(f, application):
    return f.handle_with_processors()
  elif is_class(f):
    return handle_class(f)
  elif isinstance(f, basestring):
    if f.startswith('redirect '):
      url = f.split(' ', 1)[1]
      if web.ctx.method == "GET":
        x = web.ctx.env.get('QUERY_STRING', '')
        if x:
          url += '?' + x
      raise web.redirect(url)
    elif '.' in f:
      mod, cls = f.rsplit('.', 1)
      mod = __import__(mod, None, None, [''])
      cls = getattr(mod, cls)
    else:
      cls = fvars[f]
    return handle_class(cls)
  elif hasattr(f, '__call__'):
    return f()
  else:
    return web.notfound()