使用全局，但仍然沒有在Python函數中識別

Question

我正在製作一個遊戲，您需要與怪物戰鬥，只是爲了練習我的編碼，當我遇到一個我無法理解的錯誤時。以下是代碼和我收到的錯誤：

注意：我將其更改爲完整的代碼，以便您可以看到所有內容。對不起，這是多久。

import random 
import time 

player_level = 1 
player_HP = 4 
player_mana = 2 
player_action = "Placeholder" 

entity_list = ["Nymph", "Komodo", "Free Soul"] 
current_monster_level = player_level 
current_monster_HP = random.randrange(current_monster_level, (current_monster_level * 3) + 1) 
monster_name = entity_list[random.randrange(0, 3)] 

def spawn_monster(level): 
    import random 
    global current_monster_HP 
    global monster_name 
    current_monster_HP = random.randrange(level, level * 3) 
    monster_name = entity_list[random.randrange(0, 3)] 
    print("A ", monster_name, "attacks you!") 
    print("The ", monster_name, " has ", current_monster_HP, " HP!") 

def attack(level): 
    import random 
    global monster_name 
    global current_monster_HP 
    damage = random.randrange(level, level + 4) 
    current_monster_HP = current_monster_HP - damage 
    if damage == 0: 
     print("You missed! No damage done! ", monster_name, "'s HP is ", current_monster_HP, " !") 
    elif damage > current_monster_HP: 
     damage = current_monster_HP 
     print("You did ", damage, " damage! The ", monster_name, " was defeated!") 

    else: 
     print("You did ", damage, " damage. The enemy's HP is now ", current_monster_HP, "!") 

def spell(level): 
    global player_mana 
    global player_HP 
    player_mana = player_mana - 2 
    player_HP = player_HP + level 
    print("A spell is cast, and you gain ", level, "HP!") 

def monster_retaliate(level): 
    import random 
    global player_HP 
    global monster_name 
    global current_monster_HP 
    damage = random.randrange(level, level + 2) 
    player_HP = player_HP - damage 
    print("The ", monster_name, " attacked you, dealing ", damage, " damage!") 
    if damage == 0: 
     print("The enemy missed! No damage done! Your HP is ", player_HP, "!") 
    elif damage > current_monster_HP: 
     damage = current_monster_HP 
    else: 
     print("the ", monster_name, " did ", damage, " damage. Your HP is now ", player_HP, "!") 


print("xxxxxxxxxxxxx") 
print("xxxxxxxxxxxxx") 
print("x Blind RPG x") 
print("xxxxxxxxxxxxx") 
print("xxxxxxxxxxxxx") 
print("\n") 

begin = input("Start a new game?").lower() 

if begin == "yes": 
    print("Your tale starts when your memory does. You can't remember anything!") 
    time.sleep(1) 
    print("You wake up in an empty field, and you think you see a shadowy figure.") 
    time.sleep(1) 
    print("It slips away into the faraway trees lining the grassy field, or does it?") 
    time.sleep(1) 
    print("You stand up.") 
    time.sleep(1) 
    print("You decide to go over to where the shadow left the field.") 
    time.sleep(1) 
    print("On the ground, you see a small sword. You pick it up.") 
    time.sleep(1) 
    print("Suddenly, something jumps out at you from behind a tree.") 
    time.sleep(1) 

    spawn_monster(1) 
    while current_monster_HP > 0: 
     player_action = input("What do you do?").lower() 
     if player_action == "attack": 
      attack(player_level) 
      time.sleep(2) 
      if current_monster_HP > 0: 
       monster_retaliate(1) 
      else: 
       break 
     elif player_action == "cast spell": 
      spell(player_level) 
      time.sleep(2) 
      monster_retaliate(1) 
     else: 
      print("The enemy attacked you as you stood unmoving!") 
      monster_retaliate(1) 

     if current_monster_HP <= 0: 
      print("You win! Apparently you remember how to fight!") 
      break 

     if player_HP <= 0: 
      print("You died! If only you had remembered how to fight...") 
      break 
else: 
    print("Then why did you open the game?") 

的attack()功能的工作原理，以及spell()功能都工作，這僅僅是monster_retaliate()功能，是造成麻煩。錯誤代碼是：

File "/Users/(Replacing my name for privacy)/Documents/Blind RPG.py", line 57, in monster_retaliate

player_HP = player_HP - damage NameError: name 'player_HP' is not defined

我認爲這是有趣的，看到我用global關鍵字

Answer 1

global實際上並沒有創建一個變量;它只是表示名稱應在全局範圍內定義，並且在分配給它時修改（而不是局部變量）。在嘗試訪問它之前，您仍然需要給它一個值。