Python - Element frequencies in percent range

When finding elements whose frequencies fall within a specific percentage range, we can use Python's Counter class along with percentage calculations to filter elements based on their occurrence rates.

Example

Below is a demonstration of finding elements with frequencies between 13% and 60% ?

from collections import Counter

my_list = [56, 34, 78, 90, 11, 23, 6, 56, 79, 90]

print("The list is :")
print(my_list)

start, end = 13, 60

my_freq = dict(Counter(my_list))
print("Element frequencies:", my_freq)

my_result = []
for element in set(my_list):
    percent = (my_freq[element] / len(my_list)) * 100
    print(f"Element {element}: {percent}%")
    if percent >= start and percent <= end:
        my_result.append(element)

print("The result is :")
print(my_result)

Output

The list is :
[56, 34, 78, 90, 11, 23, 6, 56, 79, 90]
Element frequencies: {56: 2, 34: 1, 78: 1, 90: 2, 11: 1, 23: 1, 6: 1, 79: 1}
Element 34: 10.0%
Element 6: 10.0%
Element 11: 10.0%
Element 78: 10.0%
Element 23: 10.0%
Element 79: 10.0%
Element 56: 20.0%
Element 90: 20.0%
The result is :
[56, 90]

How It Works

The algorithm follows these steps ?

• Count frequencies: Counter(my_list) creates a dictionary with element counts

• Calculate percentage: For each unique element, compute (frequency / total_length) * 100

• Filter by range: Include elements whose percentage falls between start and end values

• Return results: Only elements with frequencies between 13% and 60% are included

Alternative Approach Using List Comprehension

Here's a more concise version using list comprehension ?

from collections import Counter

my_list = [56, 34, 78, 90, 11, 23, 6, 56, 79, 90]
start, end = 13, 60

my_freq = Counter(my_list)
total = len(my_list)

result = [element for element in set(my_list) 
          if start <= (my_freq[element] / total) * 100 <= end]

print("Elements in percentage range:", result)

Elements in percentage range: [56, 90]

Conclusion

Use Counter to get element frequencies, then calculate percentages and filter by range. This technique is useful for data analysis when you need to identify elements with specific occurrence patterns.