I don't know how to ask the user if they want to play again and how to make it if they say y it loops back to the start or n and the game exits. I know I could use a loop but I have no idea how to use them.
import random
xp = 0
level = 1
player1 = raw_input("player1 enter name")
enemyhealth = 100
playerhealth = 100
stage2 = "false"
difficulty = raw_input("choose difficulty, rookie,pro,master,legend or god")
if difficulty == "rookie":
    enemyhealth = enemyhealth - 15
if difficulty == "pro":
    enemyhealth = enemyhealth + 10
if difficulty == "master":
    enemyhealth = enemyhealth + 35
if difficulty == "legend":
    enemyhealth = enemyhealth + 40
if difficulty == "god":
    enemyhealth = enemyhealth + 60                                                            
print ("A quick tutorial: Make sure you type you actions with no spaces,  heres a list of the moves you can perform")
print ("Punch: A simple attack that has a short range of damage but is reliable.")
print ("flyingkick: not 100 percent reliable but if pulled off correctly can deal good damage.")
print ("uppercut: A somewhat reliable move that deals decent damage.")
print ("kick: A simple attack that has a short range of damage but is reliable.")
print ("stab: can be very powerful or deal next to no damage.")
print ("shoot: deadly if it hits, less so if you miss.")
print ("A man in the street starts a fight with you, beat him!")
while enemyhealth >0:
    fight = raw_input("fight")
    if fight == "punch":
        print ("You punched the enemy")
        enemyhealth = enemyhealth - random.randint(5,10)
        xp = xp + 1
        print "the enemy now has", enemyhealth, "health"
        print "they fight back!"
        playerhealth = playerhealth - random.randint(5,10)
        if stage2 == "true":
            playerhealth = playerhealth - random.randit (0,5)
        print "you now have..", playerhealth
    elif fight =="flyingkick":
        print "you flying kicked the enemy"
        enemyhealth = enemyhealth - random.randint(5,25)
        xp = xp + 1 
        print "the enemy now has", enemyhealth, "health"
        print "they fight back!"
        playerhealth = playerhealth - random.randint(5,15)
        if stage2 == "true":
            playerhealth = playerhealth - random.randit (0,5)
        print "you now have..", playerhealth
    elif fight =="uppercut":
        print "you uppercutted the enemy"
        enemyhealth = enemyhealth - random.randint(10,25)                                      
        xp = xp + 1 
        print "the enemy now has", enemyhealth, "health"
        print "they fight back!"
        playerhealth = playerhealth - random.randint(5,15)
        if stage2 == "true":
            playerhealth = playerhealth - random.randit (1,5)
        print "you now have..", playerhealth
    elif fight =="rko":
        print "you rko'ed the enemy, out of nowhere!"
        enemyhealth = enemyhealth - random.randint(9,29)                                      
        xp = xp + 1 
        print "the enemy now has", enemyhealth, "health"
        print "they fight back!"
        playerhealth = playerhealth - random.randint(5,12)
        if stage2 == "true":
            playerhealth = playerhealth - random.randit (1,5)
        print "you now have..", playerhealth
    elif fight =="kick":
        print "you kicked the enemy"
        enemyhealth = enemyhealth - random.randint(5,10)
        xp = xp + 1 
        print "the enemy now has", enemyhealth, "health"
        print "they fight back!"
        playerhealth = playerhealth - random.randint(5,10)
        if stage2 == "true":
            playerhealth = playerhealth - random.randit (1,5)
        print "you now have..", playerhealth
    elif fight =="ninjastar":
        print "you ninjastarred the enemy"
        enemyhealth = enemyhealth - random.randint(5,20)
        xp = xp + 1 
        print "the enemy now has", enemyhealth, "health"
        print "they fight back!"
        playerhealth = playerhealth - random.randint(5,10)
        if stage2 == "true":
            playerhealth = playerhealth - random.randit (1,5)
        print "you now have..", playerhealth
    elif fight =="headbutt":
        print "you headbutted the enemy"
        enemyhealth = enemyhealth - random.randint(5,18)
        xp = xp + 1 
        print "the enemy now has", enemyhealth, "health"
        print "they fight back!"
        playerhealth = playerhealth - random.randint(5,10)
        if stage2 == "true":
            playerhealth = playerhealth - random.randit (1,5)
        print "you now have..", playerhealth
    elif fight =="deathray":
        print "you deathrayed the enemy"
        enemyhealth = enemyhealth - random.randint(1,50)
        xp = xp + 1 
        print "the enemy now has", enemyhealth, "health"
        print "they fight back!"
        playerhealth = playerhealth - random.randint(1,30)
        if stage2 == "true":
            playerhealth = playerhealth - random.randit (1,5)
        print "you now have..", playerhealth
    elif fight =="stab":
        print "you stabbed the enemy"
        enemyhealth = enemyhealth - random.randint(3,40)
        xp = xp + 1 
        print "the enemy now has", enemyhealth, "health"
        print "they fight back!"
        playerhealth = playerhealth - random.randint(2,20)
        if stage2 == "true":
            playerhealth = playerhealth - random.randit (1,5)
        print "you now have..", playerhealth
    elif fight =="shoot":
        print "you shot the enemy"
        enemyhealth = enemyhealth - random.randint(1,50)
        xp = xp + 1 
        print "the enemy now has", enemyhealth, "health"
        print "they fight back!"
        playerhealth = playerhealth - random.randint(1,30)
        if stage2 == "true":
            playerhealth = playerhealth - random.randit (1,5)
        print "you now have..", playerhealth
    if xp == 5:
       print "you leveled up! move unlocked: 'rko'"
    if xp == 7:
       print "you leveled up! move unlocked: 'ninjastar'"
    if xp == 10:
       print "you leveled up! move unlocked: 'headbutt'"
    if xp == 100:
       print " you reached the max level! move 'deathray' is now unlocked"
    if playerhealth <1:
        print "you died!"
    if enemyhealth < 1:
        print "the enemy is KO , YOU WIN , Stage 2 is unlocked and the enemy has become stronger!"
        stage2 = "true"
    else:
        None
 
     
    