attribute Error:“str”对象在循环时没有属性“items”错误

Question

def printdash():
    print('-' * 10)


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

# creates a basic set of states with some cities in them

cities = {
'CA': 'Sacramento',
'MI': 'Lansing', 
'FL': 'Tallahasee'}

# add some more cities to the list
cities['NY'] = 'Albany'
cities['OR'] = 'Eugene'

# Print out some cities
printdash()
print('New York State has: ', cities['NY'])
print('Oregon has: ', cities['OR'])

# print some states
printdash()
print 'Michigan\'s abbreviation is: ' , states['Michigan']
print 'Florida\'s abbreviation is: ', states['Florida']

# do it by using the state then cities dict. Nested dicts!
printdash()
print 'Michigan has: ', cities[states['Michigan']]
print 'Florifa has: ', cities[states['Florida']] 

# print every states abbreviation
printdash()
for states, abbrev in states.items():
    print '%s is abbreviated as %s' % (states, abbrev)
# end

# print every city in each state
printdash()
for abbrev, cities in cities.items():
    print '%s has the city %s' % (abbrev, cities)
# end

# doing both at the same time
printdash()
for state, abbrev in states.items():
    print '%s state is abbreviated %s and has city %s' % (state, abbrev,  cities[abbrev])

每次我运行它时，它将到达第54行（最后一个for循环），然后提升属性错误标志。在我的一生中，我不知道我做错了什么，因为其他两个环，建立在几乎相同的时尚工作没有问题。

在这个网站上查找其他解决方案时，我发现以前的示例比我能理解的要复杂一些，而且解决方案似乎比这个非常一般的情况更具体一些。

尚克斯！