开始日期大于日历周期的结束日期

Question

我正在尝试编写一个函数来验证包含 2 个日期（开始和结束）、目的地和价格的包裹

最初，我尝试编写一个函数来“创建”日期并将它们放在一个列表中，然后比较它们以确定结束日期是否低于开始日期，但我认为这太复杂了，所以我求助于datetime 内置模块

但是，当我尝试运行测试功能时，它会失败并输出此错误消息

File "C:\Users\Anon\Desktop\Fac\FP\pythonProject\main.py", line 65, in valideaza_pachet
    raise Exception(err)
Exception: wrong dates!

我认为我一定搞砸了 valideaza_pachet() 函数中的一个条件，但我不明白我做错了什么

代码：

import time
import calendar
from datetime import date, datetime


def creeaza_pachet(data_i, data_s, dest, pret):
    # function that creates a tourism package, data_i = beginning date, data_s = end date, dest = destination and pret = price
    return {
        "data_i": data_i,
        "data_s": data_s,
        "dest": dest,
        "pret": pret
    }


def get_data_i(pachet):
    # functie that returns the beginning date of the package
    return pachet["data_i"]


def get_data_s(pachet):
    # functie that returns the end date of the package
    return pachet["data_s"]


def get_destinatie(pachet):
    # functie that returns the destination of the package
    return pachet["dest"]


def get_pret(pachet):
    # functie that returns the price of the package
    # input: pachet - un pachet
    # output: pretul float > 0 al pachetului
    return pachet["pret"]


def valideaza_pachet(pachet):
    #functie that validates if a package was correctly introduced or not
    #it raises an Exception as ex if any of the conditions aren't met
    err = ""
    if get_data_i(pachet) < get_data_s(pachet):
        err += "wrong dates!" # if the end date is lower than the beginning date
    if get_destinatie(pachet) == " ":
        err += "wrong destination!"
    if get_pret(pachet) <= 0:
        err += "wrong price!"
    if len(err) > 0:
        raise Exception(err)


def test_valideaza_pachet():
    pachet = creeaza_pachet(datetime.strptime('24/08/2021',"%d/%m/%Y"), datetime.strptime('26/08/2021',"%d/%m/%Y"), "Galati", 9000.1)
    valideaza_pachet(pachet)
    pachet_gresit = creeaza_pachet(datetime.strptime('24/08/2021',"%d/%m/%Y"), datetime.strptime('22/08/2021',"%d/%m/%Y"), "Galati", 9000.1)
    try:
        valideaza_pachet(pachet_gresit)
        assert False
    except Exception as ex:
        assert (str(ex) == "wrong dates!\n")
    alt_pachet = creeaza_pachet(datetime.strptime('24/08/2021',"%d/%m/%Y"), datetime.strptime('22/08/2021',"%d/%m/%Y"), " ", -904)
    try:
        valideaza_pachet(alt_pachet)
        assert False
    except Exception as ex:
        assert(str(ex) == "wrong dates!\nwrong destination!\nwrong price!\n")


def test_creeaza_pachet():
    data_i_string = '24/08/2021'
    data_i = datetime.strptime(data_i_string, "%d/%m/%Y")
    data_s_string = '26/08/2021'
    data_s = datetime.strptime(data_s_string, "%d/%m/%Y")
    dest = "Galati"
    pret = 9000.1
    pachet = creeaza_pachet(data_i,data_s,dest,pret)
    assert (get_data_i(pachet) == data_i)
    assert (get_data_s(pachet) == data_s)
    assert (get_destinatie(pachet) == dest)
    assert (abs(get_pret(pachet) - pret) < 0.0001)


def run_teste():
    test_creeaza_pachet()
    test_valideaza_pachet()


def run():
    pass


def main():
    run()
    run_teste()


main()

Answer 1

这更像是一次代码审查，有点离题，但是……首先，

• 删除所有assert False - 这些不会有任何用处
• 删除 getter 函数，这只会让事情变得复杂（只要您不使用自定义类，只需在代码中使用 dict[key]）
• 删除不必要的导入，例如calendar
• 您可能还想删除 run 和 main 函数（再次令人费解） - 只需调用您需要的函数

然后您可以更改valideaza_pachet 以引发特定值错误：

def valideaza_pachet(pachet):
    if pachet["data_i"] >= pachet["data_s"]:
        raise ValueError("start date must be < end date")
    if pachet["dest"] == " ":
        raise ValueError("destination must not be empty")
    if pachet["pret"] <= 0:
        raise ValueError("price must be >= 0")
    # returns None if no exception was raised

现在要测试一个有效的包，你只需这样做

valideaza_pachet(pachet) # no exception expected

如果没有可以进行单元测试的类，测试无效包会稍微复杂一些（参见例如here） - 但您可以捕获异常并使用 try/except 的 else 子句引发 AssertionError说你想要一个例外：

try:
    valideaza_pachet(pachet_gresit)
except Exception as ex:
    print(f"successfully received exception: {ex}")
else:
    raise AssertionError("validation should have raised an Exception")

甚至

assert str(ex) == "start date must be < end date", f"got '{ex}', expected 'start date must be < end date'"

代替print 声明。