Question

我是python的新手，所以我很抱歉这是一个简单的问题，我正在创建一个程序，我需要在多个文件中共享一个全局变量。我有一个名为settings.py的文件，如下所示：

def init():
    global BACKPACK
    global SURVIVAL_TOOLS

    BACKPACK = {}
    SURVIVAL_TOOLS = {}

我import将这些设置放入另一个名为battle.py和prepare.py的文件中：

from settings import init
# battle.py #
def win_battle(animal):
    print "You do one final slash and the {} goes limp." \
          " You pick it up and start walking back to camp.".format(animal)
    init.SURVIVAL_TOOLS['meat'] = 1
    if 'camp' in init.SURVIVAL_TOOLS:
        return_to_camp()
    else:
        options = ['create a fire', 'create a camp']
        for opt in options:
            print "TEST"  # TODO: FINISH THIS METHOD

from settings import init

def gather_gear(player):
    # prepare.py #
    """
    Gather your gear from a set list of items you have available
    :type player: String
    """
    print formatter()
    print "{}! Shouts Jack as he runs towards you." \
          " Do you wanna go Hiking this weekend?" \
          " You ponder this for a second." \
          " What the hell, you think." \
          " Can't be any worse then last time." \
          " Sure, Jack! You say enthusiastically." \
          " Just let me get some things prepared.\n".format(player)

    options = {  # All the items that are available to you before you leave
        'fire starter': 1,
        'matches': randint(1, 5),  # Uses random integers as the value
        'flash light': 1,
        'sleeping bag': 1,
        'canteen cup': 1,
        'dried foods': randint(2, 6),
        'shovel': 1,
        'knife': 1,
        'pair of socks': randint(2, 10),
        'granola bars': randint(2, 5),
        'machete': 1,
        'bottle of whiskey': 1,
        'heavy jacket': 1,
        'tinder pieces': randint(3, 5)
    }

    for key in options:
        print "You have {} {}".format(options[key], key)  # Print out all your items and make it look pretty

    count = 3
    num_in_pack = 0
    print '\n'
    while count != 0:
        item = raw_input("What would you like to take with you? Choose {} items one at a time: ".format(str(count))).lower()
        if item in options and item not in init.BACKPACK:  # As long as the item is available you can use it
            init.BACKPACK[item] = options[item]  # Add the item value to your backpack constant
            count -= 1
            print "You throw a {} in your backpack".format(item)
            num_in_pack += 1
            if num_in_pack == 3:  # If you have three items, lets begin!
                print "Your backpack is now full."
                start_adventure(player)
        else:
            print "Can't bring that item."

    return init.BACKPACK

但是我在IDE中收到警告：

Cannot find reference 'SURVIVAL_TOOLS' in 'function' less... (Ctrl+F1 Alt+T) This inspection detects names that should resolve but don't. Due to dynamic dispatch and duck typing, this is possible in a limited but useful number of cases. Top-level and class-level items are supported better than instance items.

当这个程序运行时，我得到：

Traceback (most recent call last):
  File "game.py", line 1, in <module>
    from prepare import *
  File "C:\Users\thomas_j_perkins\bin\python\game\prepare.py", line 1, in <modul
e>
    from game import *
  File "C:\Users\thomas_j_perkins\bin\python\game\game.py", line 2, in <module>
    from choices import *
  File "C:\Users\thomas_j_perkins\bin\python\game\choices.py", line 3, in <modul
e>
    from prepare import BACKPACK
ImportError: cannot import name BACKPACK

我想到了将所有常量从这个question

移到一个文件中

所以我的问题是，为什么我无法使用我在settings.py文件中创建的常量变量？

编辑：

我尝试init().BACKPACK，现在收到错误：

Traceback (most recent call last):
  File "game.py", line 94, in <module>
    welcome_screen()
  File "game.py", line 85, in welcome_screen
    gather_gear(player_name)
  File "C:\Users\thomas_j_perkins\bin\python\game\prepare.py", line 45, in gathe
r_gear
    if item in options and item not in init().BACKPACK:  # As long as the item i
s available you can use it
AttributeError: 'NoneType' object has no attribute 'BACKPACK'

Answer 1

执行global BACKPACK; BACKPACK = {}时，您正在创建名为BACKPACK的模块属性。要访问它，请将from settings import init更改为import settings。这将允许您在代码中使用settings的所有模块属性：

settings.SURVIVAL_TOOLS['meat'] = 1

您还需要确保在程序中调用settings.init一次。您可以在代码中的某个位置调用它，或者更好的是，将settings.py修改为如下所示：

BACKPACK = {}
SURVIVAL_TOOLS = {}

没有函数定义，没有全局变量。第一次将模块导入任何地方时，此代码将运行。下次导入时，不会修改dicts。

跨多个文件共享全局变量

1 个答案: