Motivation While looking through excellent Programmers solutions, I found code that represented the Dart game using regular expressions, which sparked a question during my review.

import re


def solution(dartResult):
    bonus = {'S' : 1, 'D' : 2, 'T' : 3}
    option = {'' : 1, '*' : 2, '#' : -1}
    p = re.compile('(\d+)([SDT])([*#]?)')
    dart = p.findall(dartResult)
    for i in range(len(dart)):
        if dart[i][2] == '*' and i > 0:
            dart[i-1] *= 2
        dart[i] = int(dart[i][0]) ** bonus[dart[i][1]] * option[dart[i][2]]

    answer = sum(dart)
    return answer

What Are Regular Expressions?

• Used to find string patterns in text data that match conditions I set

-> Using regular expressions makes it easy to extract the desired data from large amounts of text files, and allows you to check whether the data conforms to the required format

How to Use Them

1. re module import
2. Compile according to regular expression syntax rules and search with findall findall -> https://velog.io/@beanlove97/%ED%8C%8C%EC%9D%B4%EC%8D%AC-findall-%EB%A9%94%EC%84%9C%EB%93%9C

Summary

• I should apply regular expression syntax rules while looking at examples. There are very diverse syntaxes for setting rules.

References

1. See the regular expression summary (shaun.log) https://velog.io/@wnsqud70/%EC%A0%95%EA%B7%9C%EC%8B%9D
2. Code https://school.programmers.co.kr/learn/courses/30/lessons/17682/solution_groups?language=python3
3. How to use regular expressions https://whatisthenext.tistory.com/116
4. Vegeta meme https://www.youtube.com/watch?v=nwhmV-KO1pw