Python:计算列表中重复的元素[复制]

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这个问题已经有了答案:

• How to find duplicate elements in array using for loop in Python? 15 answers
• 如何在Python中使用for循环查找数组中的重复元素?15个答案

I am new to Python. I am trying to find a simple way of getting a count of the number of elements repeated in a list e.g.

我对Python不熟。我正在寻找一种简单的方法来计算列表中重复的元素的数量。

MyList = ["a", "b", "a", "c", "c", "a", "c"]

Output:

输出:

a: 3
b: 1
c: 3

5 个解决方案

#1

You can do that using count:

你可以使用count:

my_dict = {i:MyList.count(i) for i in MyList}

>>> print my_dict     #or print(my_dict) in python-3.x
{'a': 3, 'c': 3, 'b': 1}

Or using collections.Counter:

或者使用collections.Counter:

from collections import Counter

a = dict(Counter(MyList))

>>> print a           #or print(a) in python-3.x
{'a': 3, 'c': 3, 'b': 1}

#2

Use Counter

使用计数器

>>> from collections import Counter
>>> MyList = ["a", "b", "a", "c", "c", "a", "c"]
>>> c = Counter(MyList)
>>> c
Counter({'a': 3, 'c': 3, 'b': 1})

#3

This works for Python 2.6.6

这适用于Python 2.6.6

a = ["a", "b", "a"]
result = dict((i, a.count(i)) for i in a)
print result

prints

打印

{'a': 2, 'b': 1}

#4

yourList = ["a", "b", "a", "c", "c", "a", "c"]

expected outputs {a: 3, b: 1,c:3}

期望输出{a: 3, b: 1,c:3}

duplicateFrequencies = {}
for i in set(yourList):
    duplicateFrequencies[i] = yourList.count(i)

Cheers!! Reference

干杯! !参考

#5

lst = ["a", "b", "a", "c", "c", "a", "c"]
temp=set(lst)
result={}
for i in temp:
    result[i]=lst.count(i)
print result

Output:

输出:

{'a': 3, 'c': 3, 'b': 1}