今天打算尝试一下python3.0。没想到刚开始就受挫。测试代码如下:
from wsgiref.simple_server import make_server
def hello_world_app(env,start_response):
start_response("200 OK",[("Content-type","text/plain;charset=utf-8")])
return ["Hello World"]
httpd=make_server('',8080,hello_world_app)
httpd.handle_request()
这是最最最简单的Hello World。。可是没想到啊没想到。。。
遇到问题一:
Exception happened during processing of request from ('127.0.0.1', 1199)
Traceback (most recent call last):
File "E:\phy\python3k\lib\socketserver.py", line 281, in _handle_request_noblo
ck
self.process_request(request, client_address)
File "E:\phy\python3k\lib\socketserver.py", line 307, in process_request
self.finish_request(request, client_address)
File "E:\phy\python3k\lib\socketserver.py", line 320, in finish_request
self.RequestHandlerClass(request, client_address, self)
File "E:\phy\python3k\lib\socketserver.py", line 614, in __init__
self.handle()
File "E:\phy\python3k\lib\wsgiref\simple_server.py", line 139, in handle
self.rfile, self.wfile, self.get_stderr(), self.get_environ()
File "E:\phy\python3k\lib\wsgiref\simple_server.py", line 117, in get_environ
k,v = h.split(':',1)
ValueError: need more than 1 value to unpack
说是split的时候错了,我查看了一下源码,没发现什么不对劲,但是将h输出一看,原来h中没有包含':',导致split失败。源码是这么写的:
def get_environ(self):
# other codes....
for h in self.headers:
k,v = h.split(':',1)
k=k.replace('-','_').upper(); v=v.strip()
if k in env:
continue # skip content length, type,etc.
if 'HTTP_'+k in env:
env['HTTP_'+k] += ','+v # comma-separate multiple headers
else:
env['HTTP_'+k] = v
return env
输出了一下,在客户端提交的headers里的东西几乎全部都不带':'符号,不知道是什么原因,可能和浏览器有关,我用的是IE7,先不管,让程序运行起来再说,于是我在代码上改成
for h in self.headers:
if ':' not in h:
h=h+":"
重新运行Hello World程序。
omg,又有错误。。。。。
遇到问题二:
Traceback (most recent call last):
File "E:\phy\python3k\lib\wsgiref\handlers.py", line 75, in run
self.finish_response()
File "E:\phy\python3k\lib\wsgiref\handlers.py", line 116, in finish_response
self.write(data)
File "E:\phy\python3k\lib\wsgiref\handlers.py", line 200, in write
self.send_headers()
File "E:\phy\python3k\lib\wsgiref\handlers.py", line 256, in send_headers
self.send_preamble()
File "E:\phy\python3k\lib\wsgiref\handlers.py", line 179, in send_preamble
self._write('HTTP/%s %s\r\n' % (self.http_version,self.status))
File "E:\phy\python3k\lib\wsgiref\handlers.py", line 387, in _write
self.stdout.write(data)
File "E:\phy\python3k\lib\socket.py", line 219, in write
return self._sock.send(b)
TypeError: send() argument 1 must be string or buffer, not str
观察了一下,这是在向客户端发送headers的时候发生的错误。说什么str不是string或buffer?
看了半天没找到引发错误的代码,能力有限。
于是上google去百度了一下,于是,就找到了这么一篇(http://www.velocityreviews.com/forums/t649886-socket-send-help.html ),上面说到:
“> connection.send('echo -> ' + data)
That's fine for Python 2.6, but you must use b'echo -> ' with 3.0
”
什么!还要加b前缀?。。晕死,好吧,我上python官方网站看看官方推荐的做法。
以下就是我找到的官方的例子(http://docs.python.org/3.0/library/wsgiref.html ):
from wsgiref.simple_server import make_server
# Every WSGI application must have an application object - a callable
# object that accepts two arguments. For that purpose, we're going to
# use a function (note that you're not limited to a function, you can
# use a class for example). The first argument passed to the function
# is a dictionary containing CGI-style envrironment variables and the
# second variable is the callable object (see PEP333)
def hello_world_app(environ, start_response):
status = b'200 OK' # HTTP Status
headers = [(b'Content-type', b'text/plain; charset=utf-8')] # HTTP Headers
start_response(status, headers)
# The returned object is going to be printed
return [b"Hello World"]
httpd = make_server('', 8000, hello_world_app)
print("Serving on port 8000...")
# Serve until process is killed
httpd.serve_forever()
我将这段代码复制到一个py文件中,运行,错误更多。。
Exception happened during processing of request from ('127.0.0.1', 1350)
Traceback (most recent call last):
File "E:\phy\python3k\lib\wsgiref\handlers.py", line 74, in run
self.result = application(self.environ, self.start_response)
File "demo1.py", line 12, in hello_world_app
start_response(status, headers)
File "E:\phy\python3k\lib\wsgiref\handlers.py", line 160, in start_response
assert type(status) is str,"Status must be a string"
AssertionError: Status must be a string
这是其中的一段,说状态码,也就是发送到客户端headers里的状态码必须为string。其他的错误中包括刚刚的TypeError: send() argument 1 must be string or buffer, not str
突然想起好像安装python的目录里就有例子,看了下simple_server的源码。里面是这样写的:
def demo_app(environ,start_response):
from io import StringIO
stdout = StringIO()
print("Hello world!", file=stdout)
print(file=stdout)
h = environ.items(); h.sort()
for k,v in h:
print(k,'=',repr(v), file=stdout)
start_response("200 OK", [('Content-Type','text/plain')])
return [stdout.getvalue()]
omg的。没想到啊没想到,竟也是错的。还是TypeError: send() argument 1 must be string or buffer, not str
有要去google上百度一下。找到这么一篇帖子(http://www.python-forum.org/pythonforum/viewtopic.php?f=5&p=56616 ),最后的回帖里写到:
This problem exists in Python 3 indeed. But the resulting error message is a complaint about invalid number of arguments. I wrote a bug report for that some time ago.
难道是传说中的bug?????
终于实在没辙了。。还是用回2.x吧,各位路过的大侠侠女们有类似情况并解决了的,强烈要求留下解决方法或联系方式。
谢谢先了。