Python: count repeated elements in the list

Question

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.

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

Output:

a: 3
b: 1
c: 3

Asked By: Jojo

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Source

Answer 1

You can do that using 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:

from collections import Counter

a = dict(Counter(MyList))

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

Answered By: sshashank124

Answer 2

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

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

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

Cheers!! Reference

Answered By: Daniel Adenew

Answer 3

In [2]: MyList = ["a", "b", "a", "c", "c", "a", "c"]

In [3]: count = {}

In [4]: for i in MyList:
   ...:     if not i in count:
   ...:         count[i] = 1
   ...:     else:
   ...:         count[i] +=1
   ...:

In [5]: count
Out[5]: {'a': 3, 'b': 1, 'c': 3}

Answered By: Nishant Nawarkhede

Answer 4

Use Counter

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

Answered By: Jayanth Koushik

Answer 5

This works for Python 2.6.6

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

prints

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

Answered By: Peter Kelly

Python: count repeated elements in the list

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