Advent of Code 2023 (Python) - Day 1

total_part1 = 0
total_part2 = 0

digit_words = {'one':'1', 'two':'2', 'three':'3', 'four':'4', 'five':'5', 'six':'6',
'seven':'7', 'eight':'8', 'nine':'9'}

with open('input.txt', 'r') as f:
    for line in f.readlines():
        # part 1
        digits = [char for char in line.strip() if char.isdigit()]
        calib = int(digits[0] + digits[-1])
        total_part1 += calib

        # part 2
        s = line.strip()

        # first digit
        first_digit = None
        for i in range(len(s)):
            if s[i].isdigit():
                first_digit = s[i]
                break
            for word in digit_words:
                if s[i:].startswith(word):
                    first_digit = digit_words[word]
                    break
            if first_digit:
                break

        # last digit
        last_digit = None
        for i in range(len(s)-1, -1, -1):
            if s[i].isdigit():
                last_digit = s[i]
                break
            for word in digit_words:
                if s[i:].startswith(word):
                    last_digit = digit_words[word]
                    break
            if last_digit:
                break

        calib = int(first_digit + last_digit)
        total_part2 += calib

# part 1
print(total_part1)

# part 2
print(total_part2)