CODEWITHSUNDEEP
pythoncounter
JamalCrawford..
JamalCrawford..

Reputation: 187

python counter with target value

I am trying to take,as arguments, two values: a list and a target value. It returns the # number of times that the target value appears in the list.

def countTarget(myList, target):
    #initialize the counter to  zero
    counter =   0
    for element in  myList:
        #compare    the value   in  the list to the target  value
        #if they    are the same,   increment   the counter
        if  element ==  target:
            counter =   counter +   1
    return  counter

Upvotes: 0

Views: 2132

Answers (2)

Jimmy Huch
Jimmy Huch

Reputation: 4550

Use the Counter class. It's a special type of dict that works very well for counting the frequency of a particular value inside a list (as opposed to using a dict yourself) because it will circumvent some nits like running into a KeyError when trying to count a target that doesn't exist in the list (Counter on the other hand will just return 0).

from collections import Counter

def countTarget(myList, target):
  return Counter(myList)[target]

Alternatively, you can use the bult in count function for lists, as mentioned in a comment below your question.

def countTarget(myList, target): return myList.count(target)

However, at that point your countTarget function isn't doing you much good. If you really want to have both objects be parameters, you can also use the count function from a static context...

list.count(myList, target)

But seriously, just use myList.count(target). It's probably the most simple and straightforward for your use case (by the looks of it). If you need to count targets multiple times, then consider keeping your own Counter as mentioned before.

Upvotes: 0

Gijs
Gijs

Reputation: 10901

Okay there are going to be better answers, but here's one.

def countTarget(myList, target):
    return sum([x == target for x in myList])

Edit

There's a much better alternative in the comments.

myList.count(target)

...

Upvotes: 2

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