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# Python – Fractional Frequency of elements in List

• Last Updated : 02 Sep, 2020

Given a List, get fractional frequency of each element at each position.

Input : test_list = [4, 5, 4, 6, 7, 5, 4, 5, 4]
Output : [‘1/4’, ‘1/3’, ‘2/4’, ‘1/1’, ‘1/1’, ‘2/3’, ‘3/4’, ‘3/3’, ‘4/4’]
Explanation : 4 occurs 1/4th of total occurrences till 1st index, and so on.

Input : test_list = [4, 5, 4, 6, 7, 5]
Output : [‘1/2’, ‘1/2’, ‘2/2’, ‘1/1’, ‘1/1’, ‘2/2’]
Explanation : 4 occurs 1/2th of total occurrences till 1st index, and so on.

Method : Using Counter() + loop + dictionary comprehension

In this, we use Counter() to get the frequency of each element in list and to form denominator part of fraction. Numerator is initialized to 0 for each element. Then loop is used to add the elements in numberator and join with total frequency in denominator.

## Python3

 `# Python3 code to demonstrate working of ``# Fractional Frequency of elements in List``# Using Counter() + loop + dictionary comprehension``from` `collections ``import` `Counter`` ` `# initializing list``test_list ``=` `[``4``, ``5``, ``4``, ``6``, ``7``, ``5``, ``4``, ``5``, ``4``, ``6``, ``4``, ``6``]`` ` `# printing original list``print``(``"The original list is : "` `+` `str``(test_list))`` ` `# initializing numerator``numer ``=` `{idx : ``0` `for` `idx ``in` `set``(test_list)}`` ` `# initializing denominator``denom ``=` `Counter(test_list)`` ` `res ``=` `[]``for` `ele ``in` `test_list:``     ` `    ``# increasing counter ``    ``numer[ele] ``+``=` `1``    ``res.append(``str``(numer[ele]) ``+` `'/'` `+` `str``(denom[ele]))`` ` `# printing result ``print``(``"Fractional Frequency List : "` `+` `str``(res))`
Output
```The original list is : [4, 5, 4, 6, 7, 5, 4, 5, 4, 6, 4, 6]
Fractional Frequency List : ['1/5', '1/3', '2/5', '1/3', '1/1', '2/3', '3/5', '3/3', '4/5', '2/3', '5/5', '3/3']

```

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