“不支持的操作数类型”错误消息

Question

获取捐赠信息并对其进行处理以生成捐赠信息的程序 为用户报告

def percent_of_target(donation, goal):
    """returns a float representing the percentage of the overall goal that 
    is contributed by the given donation"""
    result = donation / goal
    result_percentage = result * 100
    return result_percentage

def categorise_donations(donations, campaign_goal):
    """return a list of tuples with the first value of the tuple being the 
    amount donated and the second value being the category for that donation"""
    my_list = []
    for donation in donations:
        percentage = percent_of_target(donation, campaign_goal)
        # append to list and continue
    return my_list

def main():
    """Gets information from the user and then prints a report using functions
    that you have written through this quiz"""
    input_donations = []
    goal_amount = input('Campaign goal: ')
    print('Enter the donations received.')
    continue_program = True
    while continue_program == True:
        donation = input('Amount donated? ')
        if donation.isalpha() == True:
            if donation.lower() == 'q':
                continue_program = False
        else:
            input_donations.append(donation)
    donations = categorise_donations(input_donations, goal_amount)
    # print the table and exit

main()

shell中的输出：

Python 3.8.4 (v3.8.4:dfa645a65e, Jul 13 2020, 10:45:06) 
[Clang 6.0 (clang-600.0.57)]
Type "help", "copyright", "credits" or "license" for more information.
[evaluate Ass2(q6).py]
Campaign goal: 1000.00
Enter the donations received.
Amount donated? 10.00
Amount donated? 100.00
Amount donated? 1001.00
Amount donated? Q
Traceback (most recent call last):
  File "/Users/oscarevans/Library/Mobile Documents/com~apple~CloudDocs/Documents/Ass2(q6).py", line 102, in <module>
    main()
  File "/Users/oscarevans/Library/Mobile Documents/com~apple~CloudDocs/Documents/Ass2(q6).py", line 98, in <module>
    donations = categorise_donations(input_donations, goal_amount)
  File "/Users/oscarevans/Library/Mobile Documents/com~apple~CloudDocs/Documents/Ass2(q6).py", line 50, in <module>
    percentage = percent_of_target(donation, campaign_goal)
  File "/Users/oscarevans/Library/Mobile Documents/com~apple~CloudDocs/Documents/Ass2(q6).py", line 41, in <module>
    result = donation / goal
builtins.TypeError: unsupported operand type(s) for /: 'str' and 'str'

注:

• 当输入“Q”或“Q”作为“捐赠金额”的输入时，该函数用于退出while循环并停止接受捐赠

• 该程序是为了打印一个表格，表格中输入的捐赠价值和捐赠金额的类别

Answer 1

您的捐赠值（和目标）都是字符串。一旦您确定没有看到'q'输入提示您提前退出，您可能应该立即将它们转换为数字数据类型

试着这样做：

goal_amount = float(input('Campaign goal: '))    # convert to float
print('Enter the donations received.')
continue_program = True
while continue_program == True:
    donation = input('Amount donated? ')
    if donation.isalpha() == True:
        if donation.lower() == 'q':
            continue_program = False
    else:
        input_donations.append(float(donation))  # here too