笨辦法學Python3 習題39和習題40

習題38 列表的操作

# create a mapping of state to an abbreviation
states = {
    'Oregon': 'OR',
    'Florida': 'FL',
    'California': 'CA',
    'New York': 'NY',
    'Michigan': 'MI'
}

# create a basic set of states and some cities in them
cities = {
    'CA': 'San Francisco',
    'MI': 'Detroit',
    'FL': 'Jacksonville'
}

# add some more cities
cities['NY'] = 'New York'
cities['OR'] = 'Poland'

# print out some cities
print('-' * 10)
print("NY State has: ", cities['NY'])
print("OR State has: ", cities['OR'])

# print some states
print('-' * 10)
print("Michigan's abbreviation is: ", states['Michigan'])
print("Florida's abbreviation is: ", states['Florida'])

# do it by using the state then cities dict
print('-' * 10)
print("Michigan has: ", cities[states['Michigan']])
print("Florida has: ", cities[states['Florida']])

# print every state abbreviation
print('-' * 10)
for state, abbrev in states.items():
    print("%s is abbreviated %s" % (state, abbrev))

# print every city in state
print('-' * 10)
for abbrev, city in cities.items():
    print("%s has the city %s" % (abbrev, city))

# now do both at the same time
print('-' * 10)
for state, abbrev in states.items():
    print("%s state is abbreviated %s and has city %s" % (state, abbrev, cities[abbrev]))

print('-' * 10)
# safely get a abbreviation by state that might not be there
state = states.get('Texas', None)

if not state:
    print("Sorry, no Texas.")

# get a city with a default value
city = cities.get('TX', 'Does Not Exist')
print("The city for the state 'TX' is: %s" % city)

習題39 字典，可愛的字典

class Song(object):

    def __init__(self, lyrics):
        self.lyrics = lyrics

    def sing_me_a_song(self):
        for line in self.lyrics:
            print(line)


happy_birthday = Song(["Happy birthday to you", "I don't want to get sued", "So I'll stop right there"])

bulls_on_parade = Song(["They really around the family", "With pockets full of shells"])

happy_birthday.sing_me_a_song()

bulls_on_parade.sing_me_a_song()