Question

I have a pretty simple python webserver that returns a few web pages, and it keeps throwing TypeError: 'str' does not support the buffer interface. Here is my code, can anyone tell what is wrong?

from os import curdir
from os.path import join as pjoin
from http.server import BaseHTTPRequestHandler, HTTPServer
class StoreHandler(BaseHTTPRequestHandler):
    def do_GET(self):
        if self.path == "/store.json":
            with open(pjoin(curdir, 'store.json')) as fh:
                self.send_response(200)
                self.send_header('Content-type','text/json')
                self.end_headers()
                self.wfile.write(fh.read())
        elif self.path == "/Stock.htm":
            with open(pjoin(curdir, 'stock.htm')) as fh:
                self.send_response(200)
                self.send_header('Content-type','text/html')
                self.end_headers()
                self.wfile.write(fh.read())
        else:
            with open(pjoin(curdir, 'index.htm')) as fh:
                self.send_response(200)
                self.send_header('Content-type','text/html')
                self.end_headers()
                self.wfile.write(fh.read())
    def do_POST(self):
        if self.path == '/store.json':
            length = self.headers.getheader('content-length')
            data = self.rfile.read(int(length))
            with open(pjoin(curdir, 'store.json'), 'w') as fh:
                fh.write(data)
            self.send_response(200)

server = HTTPServer(('', 8080), StoreHandler)
server.serve_forever()

Here is the exception output:

127.0.0.1 - - [30/Oct/2012 16:48:17] "GET / HTTP/1.1" 200 -
----------------------------------------
Exception happened during processing of request from ('127.0.0.1', 58645)
Traceback (most recent call last):
  File "C:\Program Files\Python33\lib\socketserver.py", line 306, in _handle_request_noblock
    self.process_request(request, client_address)
  File "C:\Program Files\Python33\lib\socketserver.py", line 332, in process_request
    self.finish_request(request, client_address)
  File "C:\Program Files\Python33\lib\socketserver.py", line 345, in finish_request
    self.RequestHandlerClass(request, client_address, self)
  File "C:\Program Files\Python33\lib\socketserver.py", line 666, in __init__
    self.handle()
  File "C:\Program Files\Python33\lib\http\server.py", line 400, in handle
    self.handle_one_request()
  File "C:\Program Files\Python33\lib\http\server.py", line 388, in handle_one_request
    method()
  File "C:\Users\Arlen\Desktop\Stock Recorder\webserver.py", line 25, in do_GET
    self.wfile.write(fh.read())
  File "C:\Program Files\Python33\lib\socket.py", line 317, in write
    return self._sock.send(b)
TypeError: 'str' does not support the buffer interface
----------------------------------------

Update: Here is how my updated code looks:

from os import curdir
from os.path import join as pjoin

from http.server import BaseHTTPRequestHandler, HTTPServer

class StoreHandler(BaseHTTPRequestHandler):
    def do_GET(self):
        if self.path == "/store.json":
            with open(pjoin(curdir, 'store.json')) as fh:
                self.send_response(200)
                self.send_header('Content-type','text/json')
                self.end_headers()
                self.wfile.write(fh.read(), 'rb')
        elif self.path == "/Stock.htm":
            with open(pjoin(curdir, 'stock.htm')) as fh:
                self.send_response(200)
                self.send_header('Content-type','text/html')
                self.end_headers()
                self.wfile.write(fh.read(), 'rb')
        else:
            with open(pjoin(curdir, 'index.htm')) as fh:
                self.send_response(200)
                self.send_header('Content-type','text/html')
                self.end_headers()
                self.wfile.write(fh.read(),'rb')
    def do_POST(self):
        if self.path == '/store.json':
            length = self.headers.getheader('content-length')
            data = self.rfile.read(int(length))
            with open(pjoin(curdir, 'store.json'), 'w') as fh:
                fh.write(data)
            self.send_response(200)

server = HTTPServer(('', 8080), StoreHandler)
server.serve_forever()

Answer 1

Sockets send and receive bytes, but you are attempting to send over unicode strings since you opened the file without specifying the mode (remember, in Python 3 all strings are unicode by default).

You can either:

• Use the bytes built-in function to transform the data

– or –

• Open the file in binary mode – change open(pjoin(curdir, 'a.file')) to open(pjoin(curdir, 'store.json'), 'rb') (note the additional rb parameter).