我的变量在Python中是未定义的

我试图挑战自己，从头开始创建一个程序来帮助解决错误，等等

所以我做了一个简单的邮票商店，它对不同的邮票书籍有不同的价值。我现在想计算一下每件在征税后的价格。我试图设置一个if/elif/else语句来计算每个邮票的价格。这是我目前掌握的代码

''' #每枚邮票包括税的价格是多少

    number_of_stamps_purchased = 10

    # calculate government sales taxes on stamps 13%

    sales_tax = 0.13
    # number of stamps in each booklet

    single_stamp = 1
    book_of_five = 5
    book_of_ten = 10
    book_of_fifteen = 15
    book_of_twenty = 20
   
    # pricing chart for each book of stamps
    single = 1.50
    five = 7.00
    ten = 10.00
    fifteen = 14.00
    twenty = 16.00
  
    # price list for customers
    print('''Welcome to my stamp shop!

    Please review our price list:

    Single Stamp $1.50
    Book of 5 Stamps $7.00
    Book of 10 Stamps $10.00
    Book of 15 Stamps $14.00
    Book of 20 Stamps $16.00

    (Does not include sales tax)''')

    # conditions for total price calculation of stamps purchased

    def stamp_cost(price_per_piece):
    if number_of_stamps_purchased <= 4:
    print('''
    Your stamp cost:''',((single * sales_tax / single_stamp) + single) * number_of_stamps_purchased)
      elif number_of_stamps_purchased == 5:
        print('''
    Your stamp cost:''',((five * sales_tax) + five))
      elif number_of_stamps_purchased == 10:
        print('''
    Your stamp cost:''',((ten * sales_tax) + ten))
      elif number_of_stamps_purchased == 15:
        print('''
     Your stamp cost:''',((fifteen * sales_tax) + fifteen))
      elif number_of_stamps_purchased == 20:
        print('''
    Your stamp cost:''',((twenty * sales_tax) + twenty))
      else:
        print('Error')'''

    # calculate the per piece price based on their savings when purchasing a book
    print(total_price / number_of_stamps_purchased)

购买的邮票数量=10
#计算邮票的政府销售税13%
销售税=0.13
#每本小册子内的邮票数目
单张邮票=1
五本书=5本
十本书中的十本=10本
第十五册=15册
二十本书=20本
#每本邮票的定价表
单个=1.50
五=7.00
十=10.00
15=14.00
二十=16.00
#顾客价目表
欢迎来到我的邮票店！
请查看我们的价格表：
单枚邮票$1.50
一本五枚邮票$7.00
一本十枚邮票$10.00
一本十五枚邮票$14.00
一本二十枚邮票$16.00
（不包括销售税）“”）
#购买邮票的总价计算条件
def印花成本（每件价格）：
如果购买的邮票数量您从未声明名为
总价的变量，那么当您尝试使用
print打印（购买的邮票总数/价格）
时，Python会警告您不要定义它。您可以通过在最后一行之前定义一个
总价
来解决此问题。也许是这样：

def stamp_cost():  # I have removed the argument as it was unused.
    if number_of_stamps_purchased <= 4:
        total_price = ((single * sales_tax / single_stamp) + single) * number_of_stamps_purchased
        print('''
Your stamp cost:''', total_price)
    # The rest of the function with the same modification
    return total_price

total_price = stamp_cost()
print(total_price / number_of_stamps_purchased)

def stamp_cost（）：#我删除了未使用的参数。
如果你买了多少张邮票，像这样的东西应该会好一点。正如前面所指出的，主要问题是，您从未调用您的基金
stamp\u cost
。因此，您需要做的是将您使用
stamp\u cost
所做的操作的结果影响到您的变量
total\u price

# calculate government sales taxes on stamps 13%

sales_tax = 0.13

# pricing chart for each book of stamps
    
single = 1.50
five = 7.00
ten = 10.00
fifteen = 14.00
twenty = 16.00
    
# number of stamps in each booklet

single_stamp = 1
book_of_five = 5
book_of_ten = 10
book_of_fifteen = 15
book_of_twenty = 20
   
  
# price list for customers
print('''Welcome to my stamp shop!

Please review our price list:

Single Stamp $1.50
Book of 5 Stamps $7.00
Book of 10 Stamps $10.00
Book of 15 Stamps $14.00
Book of 20 Stamps $16.00

(Does not include sales tax)
''')

# conditions for total price calculation of stamps purchased

def stamp_cost():
    if number_of_stamps_purchased <= 4:
        total_price = (single * sales_tax / single_stamp + single) * number_of_stamps_purchased
        print('Your total cost:', total_price)
    elif number_of_stamps_purchased == 5:
        total_price = five * sales_tax + five
        print('Your total cost:',total_price)
    elif number_of_stamps_purchased == 10:
        total_price = ten * sales_tax + ten
        print('Your total cost:', total_price)
    elif number_of_stamps_purchased == 15:
        total_price = fifteen * sales_tax + fifteen
        print('Your total cost:',total_price)
    elif number_of_stamps_purchased == 20:
        total_price = twenty * sales_tax + twenty
        print('Your total cost:',total_price)
    else:
        print('Error')
    return total_price

number_of_stamps_purchased = 10

print('Number of stamp purchase:',number_of_stamps_purchased)
total_price = stamp_cost()
# calculate the per piece price based on their savings when purchasing a book
print('Price per piece:',round(total_price / number_of_stamps_purchased,2))

#计算邮票的政府销售税13%
销售税=0.13
#每本邮票的定价表
单个=1.50
五=7.00
十=10.00
15=14.00
二十=16.00
#每本小册子内的邮票数目
单张邮票=1
五本书=5本
十本书中的十本=10本
第十五册=15册
二十本书=20本
#顾客价目表
欢迎来到我的邮票店！
请查看我们的价格表：
单枚邮票$1.50
一本五枚邮票$7.00
一本十枚邮票$10.00
一本十五枚邮票$14.00
一本二十枚邮票$16.00
（不包括销售税）
''')
#购买邮票的总价计算条件
def stamp_cost（）：
如果购买了多少张邮票，你能分享完整的错误信息/回溯吗？请确保你提供的代码按原样运行，并允许重现问题。运行代码后，我发现有几个问题：a）函数中的参数
price\u per\u piece
从未使用过，所以你可以摆脱它：
def stamp_cost（）：…
。b） 
total\u price
已被使用，但从未定义（我想这是您的问题所在），因此请将值设置为
total\u price
，或者删除该特定行。可能在局部范围内使用全局变量会导致此类错误。->这对你有帮助