# Example of using a constant

PUNCTUATION = '.,"\';:!()?[]'

def normalize_word(word):
    '''returns a word all lowercase with no punctuation'''
    word = word.lower()
    for mark in PUNCTUATION:
        word = word.replace(mark, '')
    return word

#########################

class Student:
    '''Class representing a student with a name,
    an age, and a major.'''
    
    def __init__(self, name, age, major):
        '''Initializes a new student object.'''
        self.name = name
        self.age = age
        self.major = major

    def birthyear(self):
        '''Returns the birth year of the student.'''
        return 2015 - self.age
    
student1 = Student('Alice', 19, 'computer science')
student2 = Student('Bob', 20, 'biology')
print(student1.name)
print(student1.birthyear())
print(student2.name)
print(student2.birthyear())