Class to make socket behave like string

sockstr.py

'''
Small class to make a socket behave like a string.
The idea is to be able to pass an string-like thing to a parser that doesn't know in advance how much data it will require.

This requires a lot of copying; reading data is O(n**2).  It is probably better to make a parser which works off of a stream.
If the data is available as a string, but the parser works with a stream, StringIO is well behaved.
'''
class SocketString(object):
    def __init__(self, sock):
        self.sock = sock
        self.buff = ""

    def __getitem__(self, key):
        if type(key) is slice:
            self._buffer_to(key.stop)
        else:
            self._buffer_to(key)
        return self.buff[key]

    def _buffer_to(self, offset):
        more = []
        len_more = 0
        while len(self.buff) + len_more < offset:
            nxt = self.sock.recv(4096)
            len_more += len(nxt)
            more.append(nxt)
        self.buff = ''.join([self.buff]+more)


'''
>>> import socket
>>> import strsock
>>> s = socket.create_connection(('google.com', 80))
>>> s.send('fdafdsafdsa\r\n\r\n')
15
>>> strsock = sockstr.SocketString(s)
>>> strsock[:3]
'HTT'
>>> strsock[:10]
'HTTP/1.1 4'
>>> strsock[:16]
'HTTP/1.1 400 Bad'
>>> strsock[2]
'T'
'''