How do I encode a string to bytes in the send method of a socket connection in one line?

Question

In Python 3.5, using sockets, I have:

message = 'HTTP/1.1 200 OK\nContent-Type: text/html\n\n'
s.send(message.encode())

How can I do that in one line? I ask because I had:

s.send('HTTP/1.1 200 OK\nContent-Type: text/html\n\n')

but in Python 3.5 bytes are required, not a string, so this gives the error:

builtins.TypeError: a bytes-like object is required, not 'str'

Should I not be using send?

Answer 1

str, the type of text, is not the same as bytes, the type of sequences of eight-bit words. To concisely convert from one to the other, you could inline the call to encode (just as you could with any function call)...

s.send('HTTP/1.1 200 OK\nContent-Type: text/html\n\n'.encode())

.. bearing in mind that it's often a good idea to specify the encoding you want to use...

s.send('HTTP/1.1 200 OK\nContent-Type: text/html\n\n'.encode('ascii'))

... but it's simpler to use a bytes literal. Prefix your string with a b:

s.send(b'HTTP/1.1 200 OK\nContent-Type: text/html\n\n')

But you know what's even simpler? Letting someone else do HTTP for you. Have you thought about using a server such as Flask, or even the standard library, to build your app?