0

我从这个类创建了任意数量的对象：

class Person:
    def __init__(self, name, email):
        self.name = name
        self.email = email

我有这些对象的列表：

myList = []
JohnDoe = Person("John Doe", "jdoe@email.com")
BobbyMcfry = Person("Bobby Mcfry", "bmcfry@email.com")
WardWilkens = Person("Ward Wilkens", "wwilkens@email.com")
myList.append(JohnDoe)
myList.append(BobbyMcfry)
myList.append(WardWilkens)

我想检查某人是否存在，如果存在，则返回他们的属性 - 如果不存在，请说：

x = input("Who to check for? ")
for i in myList:
    if i.name == x:
        print("Name: {0}\nEmail: {1}".format(i.name, i.email))
    else:
        print("{0} is not on the manifest.".format(x))

这种方法有效，但为 myList 中的每个人返回一个或另一个 - 我只想要一个返回...

我意识到我需要做一些事情

if val in myList:....

但是我很难在不遍历每个对象的情况下如何说出“val”应该是什么

4

2 回答 2

5

使用循环很好，您只需要处理名称都不匹配的情况，您可以使用breakand轻松完成此操作else：

x = input("Who to check for? ")
for i in myList:
    if i.name == x:
        print("Name: {0}\nEmail: {1}".format(i.name, i.email))
        break
else:
    # this is only run if 'break' was not executed inside of the loop
    print("{0} is not on the manifest.".format(x))

根据您使用列表的目的，您最好使用字典将名称链接到Person对象：

myDict = {}
JohnDoe = Person("John Doe", "jdoe@email.com")
BobbyMcfry = Person("Bobby Mcfry", "bmcfry@email.com")
WardWilkens = Person("Ward Wilkens", "wwilkens@email.com")
for person in [JohnDoe, BobbyMcfry, WardWilkens]:
    myDict[person.name] = person

x = input("Who to check for? ")
person = myDict.get(x)
if person:
    print("Name: {0}\nEmail: {1}".format(person.name, person.email))
else:
    print("{0} is not on the manifest.".format(x))
于 2012-12-20T23:09:24.517 回答
1

可以使用itertools.

try:
    found_person = itertools.dropwhile(lambda person: person.name != search_name, people).next()
except StopIteration:
    found_person = None
于 2012-12-20T23:12:22.840 回答