Python-WSGI的简单尝试（Mac+Python3.7+VSCode）

环境： Mac + Python3.7 + VSCode

WSGI其实是一个借口，定义了服务器和客户端之间的标准通信格式，这样可以只要关注自己的html代码即可。

from wsgiref.simple_server import make_server

def application(environ, start_response):
    status = '200 OK'
    response_headers = [('Content-Type', 'text/html')]

    start_response(status, response_headers)

    return ['<h1> Hello, web!</h1>'.encode('utf-8')]

httpd = make_server('localhost', 8051, application)
print('Serving HTTP on port 8051...')

httpd.serve_forever()

直接在终端运行 xxx.py 就可以了

然后，在浏览器上输入 http://localhost:8051/ 就能看到 Hello, web! 了。

另外，要注意，如果在return那里没有加转码，在3.7下面就会报下面的错：

127.0.0.1 - - [02/Sep/2019 09:53:20] "GET / HTTP/1.1" 200 0
Traceback (most recent call last):
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 138, in run
    self.finish_response()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 180, in finish_response
    self.write(data)
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 266, in write
    "write() argument must be a bytes instance"
AssertionError: write() argument must be a bytes instance
127.0.0.1 - - [02/Sep/2019 09:53:20] "GET / HTTP/1.1" 500 59
----------------------------------------
Exception happened during processing of request from ('127.0.0.1', 51737)
Traceback (most recent call last):
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 138, in run
    self.finish_response()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 180, in finish_response
    self.write(data)
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 266, 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 "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 141, in run
    self.handle_error()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 368, in handle_error
    self.finish_response()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 180, in finish_response
    self.write(data)
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 274, in write
    self.send_headers()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 331, in send_headers
    if not self.origin_server or self.client_is_modern():
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 344, 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 "/anaconda3/lib/python3.7/socketserver.py", line 313, in _handle_request_noblock
    self.process_request(request, client_address)
  File "/anaconda3/lib/python3.7/socketserver.py", line 344, in process_request
    self.finish_request(request, client_address)
  File "/anaconda3/lib/python3.7/socketserver.py", line 357, in finish_request
    self.RequestHandlerClass(request, client_address, self)
  File "/anaconda3/lib/python3.7/socketserver.py", line 717, in __init__
    self.handle()
  File "/anaconda3/lib/python3.7/wsgiref/simple_server.py", line 133, in handle
    handler.run(self.server.get_app())
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 144, in run
    self.close()
  File "/anaconda3/lib/python3.7/wsgiref/simple_server.py", line 35, in close
    self.status.split(' ',1)[0], self.bytes_sent
AttributeError: 'NoneType' object has no attribute 'split'
----------------------------------------
127.0.0.1 - - [02/Sep/2019 09:53:20] "GET / HTTP/1.1" 200 0
Traceback (most recent call last):
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 138, in run
    self.finish_response()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 180, in finish_response
    self.write(data)
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 266, in write
    "write() argument must be a bytes instance"
AssertionError: write() argument must be a bytes instance
127.0.0.1 - - [02/Sep/2019 09:53:20] "GET / HTTP/1.1" 500 59
----------------------------------------
Exception happened during processing of request from ('127.0.0.1', 51739)
Traceback (most recent call last):
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 138, in run
    self.finish_response()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 180, in finish_response
    self.write(data)
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 266, 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 "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 141, in run
    self.handle_error()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 368, in handle_error
    self.finish_response()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 180, in finish_response
    self.write(data)
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 274, in write
    self.send_headers()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 331, in send_headers
    if not self.origin_server or self.client_is_modern():
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 344, 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 "/anaconda3/lib/python3.7/socketserver.py", line 313, in _handle_request_noblock
    self.process_request(request, client_address)
  File "/anaconda3/lib/python3.7/socketserver.py", line 344, in process_request
    self.finish_request(request, client_address)
  File "/anaconda3/lib/python3.7/socketserver.py", line 357, in finish_request
    self.RequestHandlerClass(request, client_address, self)
  File "/anaconda3/lib/python3.7/socketserver.py", line 717, in __init__
    self.handle()
  File "/anaconda3/lib/python3.7/wsgiref/simple_server.py", line 133, in handle
    handler.run(self.server.get_app())
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 144, in run
    self.close()
  File "/anaconda3/lib/python3.7/wsgiref/simple_server.py", line 35, in close
    self.status.split(' ',1)[0], self.bytes_sent
AttributeError: 'NoneType' object has no attribute 'split'
----------------------------------------
127.0.0.1 - - [02/Sep/2019 09:53:20] "GET / HTTP/1.1" 200 0
Traceback (most recent call last):
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 138, in run
    self.finish_response()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 180, in finish_response
    self.write(data)
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 266, in write
    "write() argument must be a bytes instance"
AssertionError: write() argument must be a bytes instance
127.0.0.1 - - [02/Sep/2019 09:53:20] "GET / HTTP/1.1" 500 59
----------------------------------------
Exception happened during processing of request from ('127.0.0.1', 51741)
Traceback (most recent call last):
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 138, in run
    self.finish_response()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 180, in finish_response
    self.write(data)
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 266, 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 "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 141, in run
    self.handle_error()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 368, in handle_error
    self.finish_response()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 180, in finish_response
    self.write(data)
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 274, in write
    self.send_headers()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 331, in send_headers
    if not self.origin_server or self.client_is_modern():
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 344, 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 "/anaconda3/lib/python3.7/socketserver.py", line 313, in _handle_request_noblock
    self.process_request(request, client_address)
  File "/anaconda3/lib/python3.7/socketserver.py", line 344, in process_request
    self.finish_request(request, client_address)
  File "/anaconda3/lib/python3.7/socketserver.py", line 357, in finish_request
    self.RequestHandlerClass(request, client_address, self)
  File "/anaconda3/lib/python3.7/socketserver.py", line 717, in __init__
    self.handle()
  File "/anaconda3/lib/python3.7/wsgiref/simple_server.py", line 133, in handle
    handler.run(self.server.get_app())
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 144, in run
    self.close()
  File "/anaconda3/lib/python3.7/wsgiref/simple_server.py", line 35, in close
    self.status.split(' ',1)[0], self.bytes_sent
AttributeError: 'NoneType' object has no attribute 'split'
----------------------------------------
127.0.0.1 - - [02/Sep/2019 09:53:20] "GET / HTTP/1.1" 200 0
Traceback (most recent call last):
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 138, in run
    self.finish_response()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 180, in finish_response
    self.write(data)
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 266, in write
    "write() argument must be a bytes instance"
AssertionError: write() argument must be a bytes instance
127.0.0.1 - - [02/Sep/2019 09:53:20] "GET / HTTP/1.1" 500 59
----------------------------------------
Exception happened during processing of request from ('127.0.0.1', 51743)
Traceback (most recent call last):
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 138, in run
    self.finish_response()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 180, in finish_response
    self.write(data)
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 266, 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 "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 141, in run
    self.handle_error()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 368, in handle_error
    self.finish_response()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 180, in finish_response
    self.write(data)
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 274, in write
    self.send_headers()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 331, in send_headers
    if not self.origin_server or self.client_is_modern():
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 344, 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 "/anaconda3/lib/python3.7/socketserver.py", line 313, in _handle_request_noblock
    self.process_request(request, client_address)
  File "/anaconda3/lib/python3.7/socketserver.py", line 344, in process_request
    self.finish_request(request, client_address)
  File "/anaconda3/lib/python3.7/socketserver.py", line 357, in finish_request
    self.RequestHandlerClass(request, client_address, self)
  File "/anaconda3/lib/python3.7/socketserver.py", line 717, in __init__
    self.handle()
  File "/anaconda3/lib/python3.7/wsgiref/simple_server.py", line 133, in handle
    handler.run(self.server.get_app())
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 144, in run
    self.close()
  File "/anaconda3/lib/python3.7/wsgiref/simple_server.py", line 35, in close
    self.status.split(' ',1)[0], self.bytes_sent
AttributeError: 'NoneType' object has no attribute 'split'
----------------------------------------
127.0.0.1 - - [02/Sep/2019 09:53:25] "GET / HTTP/1.1" 200 0
Traceback (most recent call last):
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 138, in run
    self.finish_response()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 180, in finish_response
    self.write(data)
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 266, in write
    "write() argument must be a bytes instance"
AssertionError: write() argument must be a bytes instance
127.0.0.1 - - [02/Sep/2019 09:53:25] "GET / HTTP/1.1" 500 59
----------------------------------------
Exception happened during processing of request from ('127.0.0.1', 51748)
Traceback (most recent call last):
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 138, in run
    self.finish_response()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 180, in finish_response
    self.write(data)
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 266, 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 "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 141, in run
    self.handle_error()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 368, in handle_error
    self.finish_response()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 180, in finish_response
    self.write(data)
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 274, in write
    self.send_headers()
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 331, in send_headers
    if not self.origin_server or self.client_is_modern():
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 344, 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 "/anaconda3/lib/python3.7/socketserver.py", line 313, in _handle_request_noblock
    self.process_request(request, client_address)
  File "/anaconda3/lib/python3.7/socketserver.py", line 344, in process_request
    self.finish_request(request, client_address)
  File "/anaconda3/lib/python3.7/socketserver.py", line 357, in finish_request
    self.RequestHandlerClass(request, client_address, self)
  File "/anaconda3/lib/python3.7/socketserver.py", line 717, in __init__
    self.handle()
  File "/anaconda3/lib/python3.7/wsgiref/simple_server.py", line 133, in handle
    handler.run(self.server.get_app())
  File "/anaconda3/lib/python3.7/wsgiref/handlers.py", line 144, in run
    self.close()
  File "/anaconda3/lib/python3.7/wsgiref/simple_server.py", line 35, in close
    self.status.split(' ',1)[0], self.bytes_sent
AttributeError: 'NoneType' object has no attribute 'split'
----------------------------------------

虽然一大堆，但是我们看最前面提示的 “AssertionError: write() argument must be a bytes instance”，意思就是需要 bytes 类型的，而我们直接返回的字符串，所以才会出错。