Question

I have an arbitrary number of objects created from this class:

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

I have a list of these objects:

myList = []
JohnDoe = Person("John Doe", "[e-mail]")
BobbyMcfry = Person("Bobby Mcfry", "[e-mail]")
WardWilkens = Person("Ward Wilkens", "[e-mail]")
myList.append(JohnDoe)
myList.append(BobbyMcfry)
myList.append(WardWilkens)

I am wanting to check if someone exists, and if so, return their attributes – if not, say so:

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))

This kind of works, but returns one or the other for each Person in myList – I only want one return…

I realize I need to do some sort of

if val in myList:....

But I’m having trouble how to word what “val” should be without iterating through each object

Answer 1

Using the loop is fine, you just need to handle the case where none of the names matched, you can do this easily using break and 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))

Depending on what you use the list for, you might be better of using a dictionary to link names to Person objects:

myDict = {}
JohnDoe = Person("John Doe", "[e-mail]")
BobbyMcfry = Person("Bobby Mcfry", "[e-mail]")
WardWilkens = Person("Ward Wilkens", "[e-mail]")
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))