Convert curl command to BIG-IP Monitor Send String

I'd like to say first that this is a great piece of code that has saved me a lot of headaches so thank you for creating it. The original script runs great in Python2 but had need for it to run natively in Python3 as the interpreter. This is a modified version that works in Python3.

    Code

import getopt
import sys
from urllib.parse import splithost, splittype

optlist, args = getopt.getopt(sys.argv[1:], 'X:H:d:')
flat_optlist = dict(optlist)

method = flat_optlist.get('-X', 'GET')

(host, uri) = splithost(splittype(args[0])[1])
protocol = 'HTTP/1.1'

headers = ["%s %s %s" % (method, uri, protocol)]
headers.extend([h[1] for h in optlist if h[0] == '-H'])
if not fil`text`ter(lambda x: 'host:' in x.lower(), headers):
    headers.insert(1, 'Host: %s' % (host))

send_string = "\\r\\n".join(headers)
send_string += "\\r\\n\\r\\n"

if '-d' in flat_optlist:
    send_string += flat_optlist['-d'].replace('\n', '\\n')
send_string = send_string.replace("\"", "\\\"")
print("SEND STRING: " + send_string)