ImportError: cannot import name Counter

Question

I have tried using Counter() but everytime I do:

from collections import Counter

I get an error saying:

Traceback (most recent call last):
  File "<web session>", line 1, in <module>
ImportError: cannot import name Counter

Do I actually have to make a file that has counter in it and then import it from there or something? I am a beginner so only the most basic answer will do.

Answer 1

Counter is only supported python2.7 and higher and is not available in earlier versions.

Answer 2

Use

from collections import Counter

and be sure that the C letter of Counter is a capital letter.

Answer 3

You can just cast the list to a set instead:

l = ['a','b', 'c', 'a', 'd', 'e', 's', 'd', 'e', 'c']
print (len(set(l)) #prints  6

Answer 4

I don't think that you want to use Counter from collections. Counter is used when you want to do something like count the number of occurrences of each word. For example:

from collections import Counter
Counter(['dog','cat','dog']) # Should output Counter({'dog': 2, 'cat': 1})

To count the number of distinct words in a list, you might try using the following:

len(set(yourList))

of to avoid duplicates with different cases:

len(set(word.lower() for word in yourList))

A set is allowed to contain only one instance of the items it contains, unlike a list.

You might have an earlier version of Python that doesn't include Counter in the standard library. If that is the case, you should update to a newer version if you can.

Answer 5

Rename your file as may your file named as collections or Counter. After that this will works

Answer 6

In Python3

import collections
a=collections.Counter(list(i for i in input()))
print(a)

input- aaabbbcccc

output- Counter({'c': 4, 'a': 3, 'b': 3})

if you want elements then use a.elements() , for getting values use a.values()