Python Counter-1

Counters in Python | Set 2 (Accessing Counters)

Last Updated: 04-02-2020

Counters in Python | Set 1 (Initialization and Updation)

Once initialized, counters are accessed just like dictionaries. Also, it does not raise the KeyValue error (if key is not present) instead the value’s count is shown as 0.

Example :

# Python program to demonstrate accessing of

# Counter elements

from collections import Counter

  

# Create a list

z = ['blue', 'red', 'blue', 'yellow', 'blue', 'red']

col_count = Counter(z)

print(col_count)

  

col = ['blue','red','yellow','green']

  

# Here green is not in col_count 

# so count of green will be zero

for color in col:

    print (color, col_count[color])




Output:

Counter({'blue': 3, 'red': 2, 'yellow': 1})
blue 3
red 2
yellow 1
green 0

elements() :
The elements() method returns an iterator that produces all of the items known to the Counter.
Note : Elements with count <= 0 are not included.

Example :

# Python example to demonstrate elements() on

# Counter (gives back list)

from collections import Counter

  

coun = Counter(a=1, b=2, c=3)

print(coun)

  

print(list(coun.elements()))




Output :

Counter({'c': 3, 'b': 2, 'a': 1})
['a', 'b', 'b', 'c', 'c', 'c']

most_common() :
most_common() is used to produce a sequence of the n most frequently encountered input values and their respective counts.

# Python example to demonstrate most_elements() on

# Counter

from collections import Counter

  

coun = Counter(a=1, b=2, c=3, d=120, e=1, f=219)

  

# This prints 3 most frequent characters

for letter, count in coun.most_common(3):

    print('%s: %d' % (letter, count))




f: 219
d: 120
c: 3

source: https://www.geeksforgeeks.org/counters-in-python-set-2-accessing-counters/

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Also refer:https://www.tutorialspoint.com/counters-in-python