class Book:
def __init__(self, title = None, author = None, year = None):
self.title = title
self.author = author
self.year = year
def display(self):
text = ""
if self.title != None: text = text + self.title[0:30] + " "
if self.author != None: text = text + self.author[0:20] + " "
if self.year != None: text = text + str(self.year)[0:5] + ""
print(text)
book = Book('book', 'Author', 1234567)
book.display()
