python error TypeError: a bytes-like object is required,not 'str'

Question

connectionSocket.send("%s\r\n%s\r\n\r\n" %(first_header.encode(encoding='utf_8'), following_header.encode(encoding='utf_8')))

Answer 1

You are still sending a str string object, because you used a string template (interpolating b'...' byte literal syntax into it).

Encode the result of the str % (params) operation instead:

data = "%s\r\n%s\r\n\r\n" % (first_header, following_header)
connectionSocket.send(data.encode(encoding='utf_8'))