Receiving an image using Python 3 Sockets - image

Question

I'm having a bit of a hard time receiving an image using sockets. I think the problem is related to the fact that sockets send both a header and the actual image, and that the two need different decoding.
This is the code:
import socket
mysock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
mysock.connect(('www.py4inf.com', 80))
mysock.send(
'GET http://www.py4inf.com/cover.jpg HTTP/1.0\n\n'.encode('utf-8'))
count = 0
fhand = open("stuff.jpg", "wb")
while True:
data = mysock.recv(512)
if len(data) < 1:
break
fhand.write(data)
mysock.close()
fhand.close()

Answer 1

Yes, there is a header. The end of it is after the first \r\n\r\n sequence. Once you see that sequence send the rest to a file. Here's a crude fix:
import socket
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as mysock:
mysock.connect(('www.py4inf.com', 80))
mysock.send(b'GET http://www.py4inf.com/cover.jpg HTTP/1.0\n\n')
header = b''
while True:
data = mysock.recv(512)
if not data:
raise RuntimeError('no header?')
header += data
# end-of-header in buffer yet?
eoh = header.find(b'\r\n\r\n')
if eoh != -1:
break
# split the header off and keep data read after it.
header,data = header[:eoh+4],header[eoh+4:]
print(header.decode())
with open("stuff.jpg", "wb") as fhand:
fhand.write(data)
while True:
data = mysock.recv(512)
if not data:
break
fhand.write(data)
Here's the header. Note that the content length is in the header, so if you were to send an HTTP request with a keepalive, you would have to read exactly that many bytes after the header. since Connection: close is specified, you only have to read until no more data is received.
HTTP/1.1 200 OK
Date: Sun, 22 May 2016 23:22:20 GMT
Server: Apache
Last-Modified: Fri, 04 Dec 2015 19:05:04 GMT
ETag: "b294001f-111a9-526172f5b7cc9"
Accept-Ranges: bytes
Content-Length: 70057
Connection: close
Content-Type: image/jpeg