Question

所以我收到错误 NameError：name＆＃39; chris＆＃39;没有定义，我怀疑它与全局变量和局部变量有关，但是我已经声明了＆＃39; chris＆＃39;作为函数中的全局变量。

下面是代码：

def ChrisFood():
    global chris
    chris = 1
    FoodSelection()

def JoshFood():
    global josh
    josh = 1
    FoodSelection()

def SamFood():
    global sam
    sam = 1
    FoodSelection()

def DanielFood():
    global daniel
    daniel = 1
    FoodSelection()

def JimFood():
    global jim
    jim = 1
    FoodSelection()

def SeanFood():
    global sean
    sean = 1
    FoodSelection()

def FoodSelection():

    global FoodSelectionWindow
    FoodSelectionWindow = Tk()
    FoodSelectionWindow.configure(bg="black")
    DateAdded = datetime.date.today

    FoodSelectionPlaceHolder = Label(FoodSelectionWindow, text = "Food selection will be added in the third iteration")
    FoodSelectionPlaceHolder.grid(columnspan=10)

    if chris == 1:
        with db:
            cursor.execute(''' INSERT INTO 'Breakfast_History' (CaloriesTotal, DateAdded, PupilNames) VALUES (?,?,?)''',
                           ([TotalCalories, DateAdded, "Chris"]))
    elif josh == 1:
        with db:
            cursor.execute(''' INSERT INTO 'Breakfast_History' (CaloriesTotal, DateAdded, PupilNames) VALUES (?,?,?)''',
                       ([TotalCalories, DateAdded, "Josh"]))
    elif sam == 1:
        with db:
            cursor.execute(''' INSERT INTO 'Breakfast_History' (CaloriesTotal, DateAdded, PupilNames) VALUES (?,?,?)''',
                       ([TotalCalories, DateAdded, "Sam"]))
    elif daniel == 1:
        with db:
            cursor.execute(''' INSERT INTO 'Breakfast_History' (CaloriesTotal, DateAdded, PupilNames) VALUES (?,?,?)''',
                       ([TotalCalories, DateAdded, "Daniel"]))
    elif jim == 1:
        with db:
            cursor.execute(''' INSERT INTO 'Breakfast_History' (CaloriesTotal, DateAdded, PupilNames) VALUES (?,?,?)''',
                       ([TotalCalories, DateAdded, "Jim"]))

    elif sean == 1:
        with db:
            cursor.execute(''' INSERT INTO 'Breakfast_History' (CaloriesTotal, DateAdded, PupilNames) VALUES (?,?,?)''',
                       ([TotalCalories, DateAdded, "Sean"]))

    db.commit()

非常感谢任何帮助，

感谢。

Answer 1

为某些内容定义全局变量并不为脚本中的所有函数定义它。这不是全球运作的方式。全局将局部变量更改为全局范围，请参阅：

x = 1

def foo():
    x = 2   #<--- is a local variable x

def bar():
    global x 
    x = 3   #<--- became the global x
    print('changing global x')

foo()
print(x) # 1
bar()    #changing global x
print(x) # 3
foo()
print(x) # 3

更改您的人员食物选择以改为通过此人：

def ChrisFood():
    FoodSelection('chris')

def JoshFood():
    FoodSelection('josh')

然后在你的FoodSelection中让它接受一个参数并if关闭它：

def FoodSelection(choice):
    #what you have in here skipping to if

    if choice == 'chris':
        #do chris things

    elif choice == 'josh':
        #do josh things

如果可能的话，不要依赖global。除了使用global

之外，总有更好的方法

如何修复NameError：name＆＃39; variablename＆＃39;没有定义？

1 个答案: