things = ['a','b','c','d','e']
print(things[1])
things[1] = '2'
print(things[1])
print(things)
list可以使用数值来进行索引，意思就是：
- １、ａ
- ２、ｂ
- ３、ｃ
-
４、ｄ
list
dictionary数据类型则是一种数据映射结构，将两个数据建立起对应关系。
与数据库中的数据字典等同。比如，部门，计量单位，或者币种。
dictionaries
# 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 ('-' * 40)
print ("NY State has: ", cities['NY'])
print ("OR State has: ", cities['OR'])
# print some states
print ('-' * 40)
print ("Michigan's abbreviation is: ", states['Michigan'])
print ("Florida's abbreviation is: ", states['Florida'])
# do it by using the state then cities dict
print ('-' * 40)
print ("Michigan has: ", cities[states['Michigan']])
print ("Florida has: ", cities[states['Florida']])
# print every state abbreviation
print ('-' * 40)
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')
if not state:
print( "Sorry, no Texas.")
# get a city with a default value
city = cities.get('TX', 'Does Not Exist')
A Dictionary Example
