Exercise 39 - dictionary

# create a mapping of state to 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‘] = ‘Portland‘

# 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))

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

print(‘-‘ * 10)
# safely get an 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 values
city = cities.get(‘TX‘, ‘Does Not Exist‘)
print("The city for the state ‘TX‘ is: %s" % city)

output

----------
NY State has:  New York
OR State has:  Portland
----------
Michigan‘s abbreviation is:  MI
Florida‘s abbreviation is:  FL
----------
Michigan has:  Detroit
Florida has:  Jacksonville
----------
Oregon is abbreviated OR
Florida is abbreviated FL
California is abbreviated CA
New York is abbreviated NY
Michigan is abbreviated MI
----------
CA has the city San Francisco
MI has the city Detroit
FL has the city Jacksonville
NY has the city New York
OR has the city Portland
----------
Oregon state is abbreviated OR and had city Portland
Florida state is abbreviated FL and had city Jacksonville
California state is abbreviated CA and had city San Francisco
New York state is abbreviated NY and had city New York
Michigan state is abbreviated MI and had city Detroit
----------
Sorry, no Texas
The city for the state ‘TX‘ is: Does Not Exist

2019-10-01

02:05:37

原文地址：https://www.cnblogs.com/petitherisson/p/11614165.html