Advent of Code 2018 Day 4 solution

sol.py

import re
import pprint
pp = pprint.PrettyPrinter(indent=2)

def Input():
    filename = './input.txt'
    return open(filename)

lines = Input().read().split('\n')

# group lines by shift
shifts = []
shift = []
for line in lines:
    if 'Guard #' in line:
        if shift:
            shifts.append(shift)
            shift = []
        shift.append(line)
    else:
        shift.append(line)
shifts.append(shift)

# group shifts by elf
elfs = {}
for shift in shifts:
    elfId = re.search('#\d+', shift[0]).group(0)
    if elfId in elfs.keys():
        elfs[elfId].append(shift)
    else:
        elfs[elfId] = [shift]

# find sleepiest elf
sleepTotals = {}
for elfId in elfs:
    elf = elfs[elfId]
    for shift in elf:
        sleepSum = 0
        #sleepBegin = 0
        for line in shift:
            if 'asleep' in line:
                sleepBegin = int(re.search(':\d+', line).group(0)[1:])
            if 'wake' in line:
                sleepEnd = int(re.search(':\d+', line).group(0)[1:])
                sleepSum += sleepEnd - sleepBegin
        if elfId in sleepTotals.keys():
            sleepTotals[elfId] += sleepSum
        else:
            sleepTotals[elfId] = sleepSum

# elf 1993 is sleepiest
# determine sleepiest minute
sleepiest = elfs['#1993']

minutes = [0 for i in range(60)]
for shift in sleepiest:
    for line in shift:
        if 'asleep' in line:
            sleepBegin = int(re.search(':\d+', line).group(0)[1:])
        if 'wake' in line:
            sleepEnd = int(re.search(':\d+', line).group(0)[1:])
            for i in range(sleepBegin, sleepEnd + 1):
                minutes[i] += 1
sleepiestMinCount = max(minutes)
sleepiestMin = 0
for i in range(len(minutes)):
    if minutes[i] == sleepiestMinCount:
        print('sleepiest min {}'.format(i))
        sleepiestMin = i
print('answer is {}'.format(1993 * sleepiestMin))