CODEWITHSUNDEEP
pythoncounter
Python Learner
Python Learner

Reputation: 167

Counting votes in a list

I am trying to count the frequency of the elements in the list. The below code is from a Data Science book, i am not able to understand the meaning of (0)[1] Please someone explain me.

from collections import Counter
def raw_majority_vote(labels):
    votes=Counter(labels)
    winner,x=votes.most_common(1)[0]
    return winner,x
l=[12,9,3,4,19,11,12,16,19,19,12,12,12,87,12,54,12]
raw_majority_vote(l)

Upvotes: 0

Views: 229

Answers (2)

el_oso
el_oso

Reputation: 1061

just to consolidate what's already mentioned in the comments.

most_common(n) returns a list of tuples in sorted order with the parameter n specifying how many of the most common objects are returned.

for example most_common(2) will return the top 2 most common objects, as a tuple with the first element of the tuple being the object name and the second element of the tuple being the count of them. Now you know that result = most_common(2) returns a list of length 2, with tuples of the object and the count. You can index into that list with [] and subsequently into the tuple with another set of []. most_common(2)[1] gets you the second most common element in the list and it's count.

In your example most_common(1) returns a list of length 1. List indexes start at 0, so to get the first tuple you use most_common(1)[0]

  • To print what object that is most_common(1)[0][0].
  • To print how many of that object there are you use most_common(1)[0][1]

Upvotes: 1

Defending Troy
Defending Troy

Reputation: 31

  from collections import Counter
  def raw_majority_vote(labels):
      votes=Counter(labels)
      winner,x=votes.most_common(1)[0]
      print(type(votes.most_common()))
      print(votes.most_common())
      print(type(votes.most_common(1)[0]))
      print(votes.most_common(1)[0])
      print(type(votes.most_common(1)[0][0]))
      print(votes.most_common(1)[0][0])
      return winner,x
  l=[12,9,3,4,19,11,12,16,19,19,12,12,12,87,12,54,12]
  raw_majority_vote(l)

it will easier to understand as above showed

Upvotes: 2

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