Oct 27
discuss & demo midterm projects
assignment
Your next assignment is posted, and due Tuesday, on chapter 10.
defining objects/classes continued ...
Questions about anything we've done?
__str__
Look at the __str__ method :
class Person(object):
def __init__(self, name=''):
self.name = name
def __str__(self):
return "Person('{}')".format(self.name)
or even just
class Foo:
def __str__(self):
return '<Foo thingimabob>'
Then try creating and printing one of 'em.
more tricks with class
An example of inheritance, a class variable, __str__, and a container class :
practice
In class coding project : create fraction.py which implements a Fraction class, which displays as i/j and implements some of the standard math operations.
It should do something like this :
>>> from fraction import Fraction
>>> Fraction(1,2) + Fraction(1/3)
4/6
(If we really want to get fancy we could have it have it convert that to 2/3 on its own ...)
aside
This takes a bit of printing and/or explaining ...
"""
functional fizzbuzz from ghost.io & hackernews
https://news.ycombinator.com/item?id=12797886
http://klipse.ghost.io/the-most-elegant-implementation-of-fizzbuzz/
"""
from itertools import cycle, imap, count, islice
from operator import add
def fizzbuzz(n):
fizzes = cycle(["", "", "Fizz"]) # . . Fizz . . Fizz . . Fizz
buzzes = cycle(["", "", "", "", "Buzz"]) # . . . . Buzz . . . .
words = imap(add, fizzes, buzzes) # . . Fizz . Buzz Fizz . . Fizz
numbers = imap(str, count(1)) # 1 2 3 4 5 6 7 8 9
_fizzbuzz = imap(max, words, numbers) # 1 2 Fizz 4 Buzz Fizz 7 8 Fizz
return islice(_fizzbuzz, n) # n terms from lazy infiite iterator
for i in fizzbuzz(100):
print i
procedural :
# http://codereview.stackexchange.com/questions/9751/ultra-beginner-python-fizzbuzz-am-i-missing-something
for num in xrange(1,101):
msg = ''
if num % 3 == 0:
msg += 'Fizz'
if num % 5 == 0:
msg += 'Buzz'
print msg or num
