Find Top Three Most Occurred Letters from Company Name in Python

Suppose we have a company name as string. We have to find the most common three characters from the company name and show them by following these rules −

• Pick most frequent three letters
• Sort them in descending order
• If the frequencies of some characters are same then take by their alphabetical order

So, if the input is like s = "TUTORIALSPOINT", then the output will be [[3, 'T'], [2, 'I'], [2, 'O']]

To solve this, we will follow these steps −

• x := a map containing letters and frequencies of letters in s
• res := a new list
• for each i in x, do
  • insert pair (x[i], i) into ret
• res := res after sorted based on alphabetical order
• res := res after sorted based on frequency in reverse order
• return first three items from res

Example

Let us see the following implementation to get better understanding

from collections import Counter
def solve(s):
   x = Counter(s)
   res = []

   for i in x:
      res.append([x[i], i])

   res = sorted(res, key=lambda cnt: cnt[1])
   res = sorted(res, key=lambda cnt: cnt[0], reverse=True)

   return res[:3]

s = "TUTORIALSPOINT"
print(solve(s))

Input

"TUTORIALSPOINT"

Output

[[3, 'T'], [2, 'I'], [2, 'O']]