max method explained

One nice thing about the max function is that you can provide a key that points to a function which basically extracts the value from the elements on which we want max to order the elements.

person1 = {}
person1['name'] = 'Valerie'
person1['age'] = 5

person2 = {}
person2['name'] = 'Robby'
person2['age'] = 35

person3 = {}
person3['name'] = 'Lindsey'
person3['age'] = 9

persons = [person1, person2, person3]

#goal find the eldest person
def getAge(person):
    return person['age']

print max(persons, key=getAge)

{'age': 35, 'name': 'Robby'}