class Post:
    label = 'tweet'

first = Post()
second = Post()
first.label = 'announcement'
Post.label = 'post'
print(first.label)
print(second.label)

import copy

feed = [['hello'], ['good morning']]
alias = feed
shallow = copy.copy(feed)
deep = copy.deepcopy(feed)
feed[0].append('an update')
feed.append(['good evening'])
print(alias)
print(shallow)
print(deep)

posts = ['morning', 'afternoon', 'evening']
newest_first = list(reversed(posts))
print(newest_first)
print(posts)
print(posts.reverse())
print(posts)

class Feed:
    def __init__(self, posts=None):
        if posts is None:
            posts = []
        self.posts = posts

first = Feed()
second = Feed()
first.posts.append('hello')
print(second.posts)