Hackerrank 2nd question

main.py

import re
from collections import Counter

def buildDictionary():
  # { "code": "char"}
  return {
    "0": "a",
    "1": "b",
    "2": "c",
    "3": "d",
    "4": "e",
    "5": "f",
    "6": "g",
    "7": "h",
    "8": "i",
    "9": "j",
    "0#": "k",
    "1#": "l",
    "2#": "m",
    "3#": "n",
    "4#": "o",
    "5#": "p",
    "6#": "q",
    "7#": "r",
    "8#": "s",
    "9#": "t",
    "20&": "u",
    "21&": "v",
    "22&": "w",
    "23&": "x",
    "24&": "y",
    "25&": "z",
  }

def frequencyCount(s):
  andsMatches = re.findall(r"((\[\d+\])?2[0-6]&)", s)
  ands = [i[0] for i in andsMatches if len(andsMatches) > 0]

  hashMatches = re.findall(r"((\[\d+\])?\d#)", s)
  hashes = [i[0] for i in hashMatches if len(hashMatches) > 0]

  digitsStr = s 
  for i in ands:
    s = s.replace(i, "")

  for i in hashes:
    s = s.replace(i, "")

  digitsMatches = re.findall(r"((\[\d+\])?\d{1,1})", s)
  digits = [i[0] for i in digitsMatches if len(digitsMatches) > 0]

  allChars = []
  for i in ands +  hashes + digits:
    if "]" in i:
      splits = i.split("]")
      multiplier = int(splits[0].replace("[", ""))
      allChars.extend([splits[1] for m in range(multiplier)])
    else:
      allChars.append(i)

  aggregated = Counter(allChars)
  check = { v : aggregated.get(k, 0) for k, v in buildDictionary().items()}
  print(check)
  results = [ aggregated.get(k, 0) for k in buildDictionary().keys()]
  return results


def main():
  data = "[2]12[4]25&24&2#5#" 
  results = frequencyCount(data)
  print(results)


if __name__ == "__main__":
  main()

## 0-9
## 0#
## 20&