Please note, this is a STATIC archive of website www.w3resource.com from 19 Jul 2022, cach3.com does not collect or store any user information, there is no "phishing" involved.
w3resource

Python: Frequency of the elements in a given list of lists using collections module

Python Collections: Exercise-29 with Solution

Write a Python program to get the frequency of the elements in a given list of lists. Use collections module.

Sample Solution:

Python Code:

from collections import Counter
from itertools import chain
nums = [
        [1,2,3,2],
        [4,5,6,2],
        [7,1,9,5],
       ]
    
print("Original list of lists:")
print(nums)
print("\nFrequency of the elements in the said list of lists:")
result = Counter(chain.from_iterable(nums))
print(result)

Sample Output:

Original list of lists:
[[1, 2, 3, 2], [4, 5, 6, 2], [7, 1, 9, 5]]

Frequency of the elements in the said list of lists:
Counter({2: 3, 1: 2, 5: 2, 3: 1, 4: 1, 6: 1, 7: 1, 9: 1})

Flowchart:

Python Collections: Frequency of the elements in a given list of lists using collections module.

Visualize Python code execution:

The following tool visualize what the computer is doing step-by-step as it executes the said program:


Python Code Editor:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous: Write a Python program to create a dictionary grouping a sequence of key-value pairs into a dictionary of lists. Use collections module.
Next: Write a Python program to count the occurrence of each element of a given list.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



Python: Tips of the Day

Find current directory and file's directory:

To get the full path to the directory a Python file is contained in, write this in that file:

import os 
dir_path = os.path.dirname(os.path.realpath(__file__))

(Note that the incantation above won't work if you've already used os.chdir() to change your current working directory, since the value of the __file__ constant is relative to the current working directory and is not changed by an os.chdir() call.)

To get the current working directory use

import os
cwd = os.getcwd()

Documentation references for the modules, constants and functions used above:

  • The os and os.path modules.
  • The __file__ constant
  • os.path.realpath(path) (returns "the canonical path of the specified filename, eliminating any symbolic links encountered in the path")
  • os.path.dirname(path) (returns "the directory name of pathname path")
  • os.getcwd() (returns "a string representing the current working directory")
  • os.chdir(path) ("change the current working directory to path")

Ref: https://bit.ly/3fy0R6m