Why does my code give this error?

Question

I am a beginning Python programmer, and I just finished my first program, Battle. But I'm having a problem. As far as I can see, all the code works fine except for one part near the end, where I get an UnboundLocalError, take a look:

Traceback (most recent call last):
File "[Dir]\Programs\Battle.py", line 210, in <module>
callUserCombat()
File "[Dir]\Programs\Battle.py", line 26, in callUserCombat
playerLeft = str(playerLeft)
UnboundLocalError: local variable 'playerLeft' referenced before assignment

And this is what it's referring to (no small amount, sorry):

#Define callUserCombat().
def callUserCombat():
    print('Your turn.')
    time.sleep(2)
    print()
    print('Choose a move:')
    print('Attack 1 [2 - 3 Damage] (1)')
    print('Attack 2 [0 - 5 Damage] (2)')
    print('Heal [Heals 0 - 6] (3)')
    playerLeft = str(playerLeft)
    enemyLeft = str(enemyLeft)
    print('Your HP: ' + playerLeft)
    print('Enemy HP: ' + enemyLeft)
    chosenAttack = input()

    while chosenAttack != '0':
        if chosenAttack == '1':
            chosenAttackPower = random.randint(2,3)
            enemyLeft = - chosenAttackPower
            chosenAttackPower = str(chosenAttackPower)
            print('You attacked!')
            print('Enemy lost ' + chosenAttackPower + 'HP. ')
            break

        if chosenAttack == '2':
            chosenAttackPower = random.randint(0,5)
            enemyLeft = - chosenAttackPower
            chosenAttackPower = str(ChosenAttackPower)
            print('You attacked!')
            print("Enemy lost " + chosenAttackPower + 'HP. ')
            break

        if chosenAttack == '3':
            chosenAttackPower = random.randint(1,5) 
            playerLeft = + chosenAttackPower
            chosenAttackPower = str(ChosenAttackPower)
            print('You healed!')
            print('Healed ' + chosenAttackPower + 'HP.')
            break

        else:
            chosenAttack = '0'
            print('Please enter a valid move code.')
            print("Attack 1 (1)")
            print("Attack 2 (2)")
            print("Heal (3)")
            print()
            chosenAttack = input()
        limitHealth()

#Define callEnemyCombat().
def callEnemyCombat():
    print('Enemy\'s turn.')
    time.sleep(2)
    print()
    enemyAttack = random.randint(1,6)
    if enemyAttack == '1':
        enemyAttackPower = random.randint(2,3)
        playerLeft = - enemyAttackPower
        enemyAttackPower = str(enemyAttackPower)
        print('Don\'t bother taunting me, you\'ll die trying. And it\'s mean.')
        print('Enemy attacked!')
        print('You lost ' + enemyAttackPower + 'HP. ')

    if enemyAttack == '2':
        enemyAttackPower = random.randint(2,3)
        playerLeft = - enemyAttackPower
        enemyAttackPower = str(enemyAttackPower)
        print('Where do you live? I only want to know so I can kill')
        print('your family once I\'m finished with you.')
        print('Enemy attacked!')
        print('You lost ' + enemyAttackPower + 'HP. ')

    if enemyAttack == '3':
        enemyAttackPower = random.randint(2,3)
        playerLeft = - enemyAttackPower
        enemyAttackPower = str(enemyAttackPower)
        print('I can take anything you can throw at me. Except Chocolate.')
        print('I\'m allergic to Chocolate.')
        print('Enemy attacked!')
        print('You lost ' + enemyAttackPower + 'HP. ')

    if enemyAttack == '4':
        enemyAttackPower = random.randint(0,5)
        playerLeft = - enemyAttackPower
        enemyAttackPower = str(enemyAttackPower)
        print('I WILL kill you, even if I have to hire the Men in Black to do it.')
        print('Enemy attacked!')
        print('You lost ' + enemyAttackPower + 'HP. ')

    if enemyAttack == '5':
        enemyAttackPower = random.randint(0,5)
        playerLeft = - enemyAttackPower
        enemyAttackPower = str(enemyAttackPower)
        print('Have you heard of pong? We could play pong after I kill you,')
        print('if you like.')
        print('Enemy attacked!')
        print('You lost ' + enemyAttackPower + 'HP. ')

    if enemyAttack == '6':
        enemyAttackPower = random.randint(1,5) 
        enemyLeft = + enemyAttackPower
        enemyAttackPower = str(ChosenAttackPower)
        print('Charging up with a cold glass of water, and a side of you.')
        print('Enemy healed!')
        print('Healed ' + chosenAttackPower + 'HP.')
    limitHealth()

#Define limitHealth().
def limitHealth():
    if playerLeft > playerHealth:
        playerLeft = playerHealth

    if enemyLeft > enemyHealth:
        enemyLeft = enemyHealth

And here is the code, so all that makes sense: (https://www.dropbox.com/s/9l4ifgmk5sx1pg1/Battle.py).

EDITED: Sorry about the post, it seemed to be quite terribly written, so I fixed.

Answer 1

definitely an issue with scope, and more specifically the way in which python resolves names when attempting to assign to it (i.e. when you're trying to assign the variable playerLeft). You can look here: http://eli.thegreenplace.net/2011/05/15/understanding-unboundlocalerror-in-python/ for a full description.

Since it seems that you are simply trying to print the value of the global variable, playerLeft. Simply do that, exactly:

playerLeft = 2
enemyLeft = 2
...

#Define callUserCombat().
def callUserCombat():

    ...
    print('Your HP: ', playerLeft) 
    print('Enemy HP: ',  enemyLeft) 

    ...

Should avoid the problem

Answer 2

It's a scope variable problem. You need to type your globals variables as such :

enemyHealth = 1
playerLeft = 2
enemyLeft = 2
...

#Define callUserCombat().
def callUserCombat():
     global enemyHealth
     global playerLeft 
     global enemyLeft 
     etc.