When the wrong code comes up ：

result = sorted(classCount.iteritems(), key=operator.itemgetter(1), reverse=True)

Error display ：

AttributeError: 'dict' object has no attribute 'iteritems'

The reason for the above error is python3 There is no such attribute in , Directly change to items that will do ：

result = sorted(classCount.items(), key=operator.itemgetter(1), reverse=True)

Knowledge points supplement ：

operator.itemgetter function

operator Module provided itemgetter Function is used to get the data of which dimensions of an object , The parameter is some sequence number （ That is, the serial number of the data to be acquired in the object ）, Let's take an example .

a = [1,2,3]
b=operator.itemgetter(1)  // Defined function b, Get the... Of the object 1 Values for domains 
print(b(a)) 

Output ：
2

b=operator.itemgetter(1,0) // Defined function b, Get the... Of the object 1 Domain and the 0 Values for domains 
print(b(a)) 

Output ：
(2, 1)

it is to be noted that ,operator.itemgetter Function does not get value , It defines a function , This function is used to get the value of an object .

Dictionaries items() Operation method ：

x = {
'title':'python web site','url':'www.iplaypy.com'}
print(x.items())

Output ：
[(‘url’, ‘www.iplaypy.com’), (‘title’, ‘python web site’)]

You can see from the results ,items() The method is to treat each item in the dictionary as a tuple , Add to a list , Form a new list container . If necessary, you can also assign the returned result to the new variable , This new variable will be a list data type .

a=x.items()
print(a)

Output ：

[(‘url’, ‘www.iplaypy.com’), (‘title’, ‘python web site’)]

print(type(a))

Output ：
<\type ‘list’>

Reference material ：Python Dictionaries items Returns a list of