Help

Ok, here is my full code. I have problems with line 42, I will indicate where it is at the end. I am basically trying to code a text based rpg. I've got the main functions but how can I make a combat system? I mean that I can ecounter an enemy, attack but how can I repeat that sequence without any errors?

import random
myhp = 50
mo_basichp = 20
mo_mediumhp = 50
mo_hardhp = 100
bosshp = 120
mydmg = random.randrange(1,10)
mo_basicdmg = random.randrange(1,5)
mo_mediumdmg = random.randrange(2,12)
mo_harddmg = random.randrange(5,20)
bossdmg = random.randrange(5,30)
mo_basic = ["Orc", "Skeleton", "Warrior", "Dwarf"]

print("The Legend of King's College")
import time
time.sleep(2)
print("Start" + " " + "Exit")
gameop = input()
if gameop == "Start" or "start":
  import sys
  from time import sleep

  words = "Once upon a time, in a far away land known as Murcia, there was a castle, that castle was King's College. There lived a mighty hero; Lucas. Now, he must face what destiny has to offer."
  for char in words:
    sleep(0.1)
    sys.stdout.write(char)
    sys.stdout.flush()
  time.sleep(2)
//Down here are the problems
  mo_basic2 = random.choice(mo_basic)
  player_inbattle = False
  player_action = [" running around.", " in a cave.", " eating lunch.", " leveling up.", " fighting goblins."]
  while True:
    print ("Lucas has encountered a " + random.choice(mo_basic))
    print ("Fight or Flight?")
    answer1 = input()
    if answer1 == "Fight":
      player_inbattle = True
      print ("Attack" + "Defend")
      answerat = input()
      if answerat == "Attack" or "attack":
        while mo_basichp > 0:
          print ("Monster has " + mo_basichp - mydmg + " hp left")
          print ("The monster attacked you!")
          print ("You have " + myhp - mo_basicdmg + " hp left.")
      break
    else:
      print ("Lucas is" + random.choice(player_action))
      time.sleep(6)