一名 Python 初学者在编写一个重量单位转换的程序时，遇到了一个语法错误，其问题在于菜单函数的名称中包含空格。

2. 解决方案

Python 变量命名规则规定，函数名称应为小写，且单词之间使用下划线 (_) 分隔，不能使用空格。因此，需要将菜单函数的名称 “display menu()” 更改为 “display_menu()”.

• 错误代码:

def display menu():
    print('          ')
    print('          ')
    print('          Menu')
    print('1. Kilograms to Ounce')
    print('2. Kilograms to Pound')
    print('3. Pound to Ounce')
    print('4. Pound to Ton')
    print('5. Ton to Pound')
    print('6. Ton to Ounce')
    print('7. Ton to Kilograms')
    print('8. Quit')

• 更正后的代码:

def display_menu():
    print('          ')
    print('          ')
    print('          Menu')
    print('1. Kilograms to Ounce')
    print('2. Kilograms to Pound')
    print('3. Pound to Ounce')
    print('4. Pound to Ton')
    print('5. Ton to Pound')
    print('6. Ton to Ounce')
    print('7. Ton to Kilograms')
    print('8. Quit')

另外，在 Python 中，缩进非常重要，它决定了代码块的范围。在上述代码中，缩进不一致，会导致程序错误，因此也需要进行修改。

• 错误代码:

def display menu():
    print('          ')
    print('          ')
    print('          Menu')
    print('1. Kilograms to Ounce')
    print('2. Kilograms to Pound')
    print('3. Pound to Ounce')
    print('4. Pound to Ton')
    print('5. Ton to Pound')
    print('6. Ton to Ounce')
    print('7. Ton to Kilograms')
    print('8. Quit')

def main():
    choice=0

    while choice != QUIT_CHOICE:
        display menu()
        choice=int(input('Enter your choice:'))

        #Perform menu choice
        if choice == CONVERT_KILOGRAMS_OUNCE:
            kilo=float(input("Enter weight in Kilograms:"))
            print('The weight in ounces is:', KilogramConversion.ounce(kilo))
        elif choice == CONVERT_KILOGRAMS_POUND:
            kilo=float(input("Enter weight in Kilograms:"))
            print('The weight in pounds is:', KilogramConversion.pound(kilo))
        elif choice == CONVERT_POUND_OUNCE:
            lbs=float(input("Enter weight in Pounds:"))
            print('The weight in ounces is:', PoundConversion.ounce(lbs))
        elif choice == CONVERT_POUND_TON:
            lbs=float(input("Enter weight in Pounds:"))
            print('The weight in tons is:', PoundConversion.ton(lbs))
        elif choice == CONVERT_TON_POUND:
            tons= float(input("Enter weight in Tons:"))
            print('The weight in pounds is:', TonConversion.pound(tons))
        elif choice == CONVERT_TON_OUNCE:
            tons= float(input("Enter weight in Tons:"))
            print('The weight in ounces is:', TonConversion.ounce(tons))
        elif choice == CONVERT_TON_KILOGRAMS:
            tons= float(input("Enter weight in Tons:"))
            print('The weight in kilograms is:', TonConversion.kilogram(tons))
        elif choice == QUIT_CHOICE:
            print('Exiting...')
        else:
            print('Invalid Selection')

• 更正后的代码:

def display_menu():
    print('          ')
    print('          ')
    print('          Menu')
    print('1. Kilograms to Ounce')
    print('2. Kilograms to Pound')
    print('3. Pound to Ounce')
    print('4. Pound to Ton')
    print('5. Ton to Pound')
    print('6. Ton to Ounce')
    print('7. Ton to Kilograms')
    print('8. Quit')


def main():
    choice = 0

    while choice != QUIT_CHOICE:
        display_menu()
        choice = int(input('Enter your choice:'))

        # Perform menu choice
        if choice == CONVERT_KILOGRAMS_OUNCE:
            kilo = float(input("Enter weight in Kilograms:"))
            print('The weight in ounces is:', KilogramConversion.ounce(kilo))
        elif choice == CONVERT_KILOGRAMS_POUND:
            kilo = float(input("Enter weight in Kilograms:"))
            print('The weight in pounds is:', KilogramConversion.pound(kilo))
        elif choice == CONVERT_POUND_OUNCE:
            lbs = float(input("Enter weight in Pounds:"))
            print('The weight in ounces is:', PoundConversion.ounce(lbs))
        elif choice == CONVERT_POUND_TON:
            lbs = float(input("Enter weight in Pounds:"))
            print('The weight in tons is:', PoundConversion.ton(lbs))
        elif choice == CONVERT_TON_POUND:
            tons = float(input("Enter weight in Tons:"))
            print('The weight in pounds is:', TonConversion.pound(tons))
        elif choice == CONVERT_TON_OUNCE:
            tons = float(input("Enter weight in Tons:"))
            print('The weight in ounces is:', TonConversion.ounce(tons))
        elif choice == CONVERT_TON_KILOGRAMS:
            tons = float(input("Enter weight in Tons:"))
            print('The weight in kilograms is:', TonConversion.kilogram(tons))
        elif choice == QUIT_CHOICE:
            print('Exiting...')
        else:
            print('Invalid Selection')