w3resource

Python: Create a list with the unique values filtered out

Python List: Exercise - 224 with Solution

Write a Python program to create a list with unique values filtered out.

  • Use collections.Counter to get the count of each value in the list.
  • Use a list comprehension to create a list containing only the non-unique values.

Sample Solution:

Python Code:

from collections import Counter
def filter_unique(lst):
  return [item for item, count in Counter(lst).items() if count > 1] 
print(filter_unique([1, 2, 2, 3, 4, 4, 5]))

Sample Output: 

[2, 4]

Flowchart:

Flowchart: Create a list with the unique values filtered out.

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 list with the non-unique values filtered out.
Next: Write a Python program to retrieve the value of the nested key indicated by the given selector list from a dictionary or list.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



Follow us on Facebook and Twitter for latest update.

Python: Tips of the Day

Given a predicate function, fn, and a prop string, this curried function will then take an object to inspect by calling the property and passing it to the predicate:

Example:

def tips_check_prop(fn, prop):
  return lambda obj: fn(obj[prop])
check_age = tips_check_prop(lambda x: x >= 25, 'age')
user = {'name': 'Owen', 'age': 25}

print(check_age(user))

Output:

True

 

We are closing our Disqus commenting system for some maintenanace issues. You may write to us at reach[at]yahoo[dot]com or visit us at Facebook