python3中自定义wsgi函数，make_server函数报错问题

#coding:utf-8

from wsgiref.simple_server import make_server

def RunServer(environ, start_response):
    start_response('200 OK', [('Content-Type', 'text/html')])
    return '<h1>Hello, web!</h1>'

if __name__ == '__main__':
    httpd = make_server('localhost', 8000, RunServer)
    print ("Serving HTTP on port 8000...")
    httpd.serve_forever()
这段代码在python2.7中可以运行，到python3.4中运行，就开始报错，报错内容如下：

Serving HTTP on port 8000...
127.0.0.1 - - [12/Apr/2016 16:44:17] "GET / HTTP/1.1" 200 0
Traceback (most recent call last):
File "C:Python34libwsgirefhandlers.py", line 138, in run
self.finish_response()
File "C:Python34libwsgirefhandlers.py", line 181, in finish_response
self.write(data)
File "C:Python34libwsgirefhandlers.py", line 267, in write
"write() argument must be a bytes instance"
AssertionError: write() argument must be a bytes instance
127.0.0.1 - - [12/Apr/2016 16:44:17] "GET / HTTP/1.1" 500 59
Traceback (most recent call last):
File "C:Python34libwsgirefhandlers.py", line 138, in run
self.finish_response()
File "C:Python34libwsgirefhandlers.py", line 181, in finish_response
self.write(data)
File "C:Python34libwsgirefhandlers.py", line 267, in write
"write() argument must be a bytes instance"
AssertionError: write() argument must be a bytes instance

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "C:Python34libwsgirefhandlers.py", line 141, in run
self.handle_error()
File "C:Python34libwsgirefhandlers.py", line 369, in handle_error
self.finish_response()
File "C:Python34libwsgirefhandlers.py", line 181, in finish_response
self.write(data)
File "C:Python34libwsgirefhandlers.py", line 275, in write
self.send_headers()
File "C:Python34libwsgirefhandlers.py", line 332, in send_headers
if not self.origin_server or self.client_is_modern():
File "C:Python34libwsgirefhandlers.py", line 345, in client_is_modern
return self.environ['SERVER_PROTOCOL'].upper() != 'HTTP/0.9'
TypeError: 'NoneType' object is not subscriptable

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
----------------------------------------
Exception happened during processing of request from ('127.0.0.1', 60566)
File "C:Python34libsocketserver.py", line 305, in _handle_request_noblock
self.process_request(request, client_address)
File "C:Python34libsocketserver.py", line 331, in process_request
self.finish_request(request, client_address)
File "C:Python34libsocketserver.py", line 344, in finish_request
self.RequestHandlerClass(request, client_address, self)
File "C:Python34libsocketserver.py", line 673, in __init__
self.handle()
File "C:Python34libwsgirefsimple_server.py", line 133, in handle
handler.run(self.server.get_app())
File "C:Python34libwsgirefhandlers.py", line 144, in run
self.close()
File "C:Python34libwsgirefsimple_server.py", line 35, in close
self.status.split(' ',1)[0], self.bytes_sent
AttributeError: 'NoneType' object has no attribute 'split'
----------------------------------------
----------------------------------------
Exception happened during processing of request from ('127.0.0.1', 60568)
----------------------------------------
127.0.0.1 - - [12/Apr/2016 16:44:18] "GET / HTTP/1.1" 200 0
Traceback (most recent call last):
File "C:Python34libwsgirefhandlers.py", line 138, in run
self.finish_response()
File "C:Python34libwsgirefhandlers.py", line 181, in finish_response
self.write(data)
File "C:Python34libwsgirefhandlers.py", line 267, in write
"write() argument must be a bytes instance"
AssertionError: write() argument must be a bytes instance
127.0.0.1 - - [12/Apr/2016 16:44:18] "GET / HTTP/1.1" 500 59
Traceback (most recent call last):
File "C:Python34libwsgirefhandlers.py", line 138, in run
self.finish_response()
File "C:Python34libwsgirefhandlers.py", line 181, in finish_response
self.write(data)
File "C:Python34libwsgirefhandlers.py", line 267, in write
"write() argument must be a bytes instance"
AssertionError: write() argument must be a bytes instance

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "C:Python34libwsgirefhandlers.py", line 141, in run
self.handle_error()
File "C:Python34libwsgirefhandlers.py", line 369, in handle_error
self.finish_response()
File "C:Python34libwsgirefhandlers.py", line 181, in finish_response
self.write(data)
File "C:Python34libwsgirefhandlers.py", line 275, in write
self.send_headers()
File "C:Python34libwsgirefhandlers.py", line 332, in send_headers
if not self.origin_server or self.client_is_modern():
File "C:Python34libwsgirefhandlers.py", line 345, in client_is_modern
return self.environ['SERVER_PROTOCOL'].upper() != 'HTTP/0.9'
TypeError: 'NoneType' object is not subscriptable

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "C:Python34libsocketserver.py", line 305, in _handle_request_noblock
self.process_request(request, client_address)
File "C:Python34libsocketserver.py", line 331, in process_request
self.finish_request(request, client_address)
File "C:Python34libsocketserver.py", line 344, in finish_request
self.RequestHandlerClass(request, client_address, self)
File "C:Python34libsocketserver.py", line 673, in __init__
self.handle()
File "C:Python34libwsgirefsimple_server.py", line 133, in handle
handler.run(self.server.get_app())
File "C:Python34libwsgirefhandlers.py", line 144, in run
self.close()
File "C:Python34libwsgirefsimple_server.py", line 35, in close
self.status.split(' ',1)[0], self.bytes_sent
AttributeError: 'NoneType' object has no attribute 'split'

猛地一看，这么多报错，一下就蒙圈了，各种google百度，各种查，google到时能查到一些，

但是英文不好，也看不太明白，百度查到的都是垃圾，根本就没用，最后硬着头皮，一点一点看源码。

首先，根据第一行的提示：

File "C:Python34libwsgirefhandlers.py", line 138, in run
self.finish_response()

我这里用的编辑器是pycharm，找到handlers.py文件的138行，按住ctrl点击文件中的finish_response()方法，

就找到self.finish_response()定义的位置了。根据第二条提示：

File "C:Python34libwsgirefhandlers.py", line 181, in finish_response
self.write(data)

发现是write方法出现错误，再按住ctrl点击write方法，找到定义write方法的位置，发现第一行就定义了一条报错：

assert type(data) is bytes, 
    "write() argument must be a bytes instance"
对照上面的报错信息，发现可能是变量data的类型，不是bytes，所以在handlers.py181行代码self.write(data)上面加一句：
data=data.encode(),再次刷新程序，发现所有报错居然都没了，程序正常运行。