Python初学者如何实现用户所选服务价格求和并输出总金额

你目前的代码逻辑已经很完整了，只需要做少量修改就能达到目标，都是你已经学过的基础语法：

1. 先修改店名、服务价格为要求的数值，同时给用户输入加小写转换，避免大小写输入不匹配的问题
2. 新增两个变量分别存储两个服务的价格，初始值设为0
3. 在每个判断分支中除了打印服务信息，同时给对应价格变量赋值，最后加总输出总金额即可

修改后的完整代码如下：

# 修改店名和对应服务价格
print("Chauncey's Vet Services\n")
print("Exam: 45")
print("Vaccinations: 32")
print("Trim Nails: 8")
print("Bath: 15\n")

exam = "exam"
vaccinations = "vaccinations"
trim_nails = "trim nails"
bath = "bath"
none = "none"

exam_price = 45
vaccination_price = 32
trim_nails_price = 8
bath_price = 15
none_price = 0

# 输入加.lower()转小写，避免大小写不匹配
first_service = input("Select first service:").lower()
second_service = input("Select second service:").lower()

# 新增两个变量存两个服务的价格，初始为0
first_cost = 0
second_cost = 0

print("\nChauncey's Vet Invoice")

if first_service == exam:
    print("Service 1 - Exam: " + str(exam_price))
    first_cost = exam_price
elif first_service == vaccinations:
    print("Service 1 - Vaccinations: " + str(vaccination_price))
    first_cost = vaccination_price
elif first_service == trim_nails:
    print("Service 1 - Trim Nails: " + str(trim_nails_price))
    first_cost = trim_nails_price
elif first_service == bath:
    print("Service 1 - Bath: " + str(bath_price))
    first_cost = bath_price
elif first_service == none:
    print("Service 1 - None: " + str(none_price))
    first_cost = none_price
else:
    print("Service 1 - None: " + str(none_price))
    first_cost = none_price


if second_service == exam:
    print("Service 2 - Exam: " + str(exam_price))
    second_cost = exam_price
elif second_service == vaccinations:
    print("Service 2 - Vaccinations: " + str(vaccination_price))
    second_cost = vaccination_price
elif second_service == trim_nails:
    print("Service 2 - Trim Nails: " + str(trim_nails_price))
    second_cost = trim_nails_price
elif second_service == bath:
    print("Service 2 - Bath: " + str(bath_price))
    second_cost = bath_price
elif second_service == none:
    print("Service 2 - None: " + str(none_price))
    second_cost = none_price
else:
    print("Service 2 - None: " + str(none_price))
    second_cost = none_price

# 计算并打印总价
total = first_cost + second_cost
print(f"Total: {total}")

运行后输入Exam和none就能得到你要求的输出效果。

内容的提问来源于stack exchange，提问作者Fazli Berisha