[2018] Remove Python 2.7 support

2018/README.md

@@ -5,7 +5,7 @@ https://adventofcode.com/2018
 ## Language
 
 This year I chose to implement in Python 2, but ported the code such that it
-works in either Python 2 or Python 3.
+works properly in Python 3. Python 2 support has been removed.
 
 ## Preparation
 

2018/day01/day01.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/1
 """
 
-from __future__ import print_function
-
 from functools import reduce
 
 

2018/day02/day02.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/2
 """
 
-from __future__ import print_function
-
 from collections import Counter, defaultdict
 from functools import reduce
 

2018/day03/day03.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/3
 """
 
-from __future__ import print_function
-
 import re
 from collections import defaultdict
 from functools import reduce

2018/day04/day04.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/4
 """
 
-from __future__ import print_function
-
 import re
 from collections import defaultdict
 

2018/day05/day05.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/5
 """
 
-from __future__ import print_function
-
 from string import ascii_lowercase
 
 

2018/day06/day06.py

@@ -4,13 +4,9 @@
 https://adventofcode.com/2018/day/6
 """
 
-from __future__ import print_function
-
 import sys
 from functools import reduce
 
-_MIN_INT = -sys.maxsize - 1
-
 
 class Point:
     """Represents a point in 2D space."""
@@ -37,10 +33,10 @@ class Rect:
     @staticmethod
     def bounding_box(points):
         """Returns a rectangle which forms the boundary of all points"""
-        min_x = sys.maxsize
-        min_y = sys.maxsize
-        max_x = _MIN_INT
-        max_y = _MIN_INT
+        min_x = float('inf')
+        min_y = float('inf')
+        max_x = float('-inf')
+        max_y = float('-inf')
 
         for point in points:
             min_x = min(min_x, point.coord_x)

2018/day07/day07.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/7
 """
 
-from __future__ import print_function
-
 import re
 from collections import defaultdict
 

2018/day08/day08.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/8
 """
 
-from __future__ import print_function
-
 
 class TreeNode:  # pylint: disable=too-few-public-methods
     """Represents a single node in the tree."""

2018/day09/day09.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/9
 """
 
-from __future__ import print_function
-
 import re
 from collections import defaultdict
 

2018/day10/day10.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/10
 """
 
-from __future__ import print_function
-
 import re
 
 _ENTRY_REGEX = re.compile(

2018/day11/day11.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/11
 """
 
-from __future__ import print_function
-
 
 def get_power_level(serial_number, coord_x, coord_y):
     """Gets the power level for a given coordinate."""

2018/day12/day12.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/12
 """
 
-from __future__ import print_function
-
 import re
 from collections import defaultdict, deque
 from functools import reduce

2018/day13/day13.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/13
 """
 
-from __future__ import print_function
-
 _TURN_ORDER = [
     -1,
     0,

2018/day14/day14.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/14
 """
 
-from __future__ import print_function
-
 
 class RecipeGenerator:
     """Generator for the recipe combinations."""

2018/day15/day15.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/15
 """
 
-from __future__ import print_function
-
 from collections import defaultdict, deque
 from operator import attrgetter
 

2018/day16/day16.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/16
 """
 
-from __future__ import print_function
-
 import re
 from collections import defaultdict
 

2018/day17/day17.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/17
 """
 
-from __future__ import print_function
-
 import re
 from collections import defaultdict
 from functools import reduce

2018/day18/day18.py

@@ -4,16 +4,11 @@
 https://adventofcode.com/2018/day/18
 """
 
-from __future__ import print_function
-
 from collections import Counter
 from operator import itemgetter
 
 
-try:
-    xrange  # pylint: disable=used-before-assignment
-except NameError:
-    xrange = range  # pylint: disable=invalid-name
+
 
 
 class LumberArea:
@@ -33,9 +28,9 @@ def __init__(self, file_content):
 
     def __str__(self):
         lines = []
-        for row_index in xrange(self.max_rows + 1):
+        for row_index in range(self.max_rows + 1):
             line = []
-            for cell_index in xrange(self.max_cells + 1):
+            for cell_index in range(self.max_cells + 1):
                 line.append(self.area[(row_index, cell_index)])
             lines.append(''.join(line))
 
@@ -48,8 +43,8 @@ def get_counts(self):
     def execute_minute(self):
         """Executes a single minute of growth."""
         area_copy = self.area.copy()
-        for row_index in xrange(self.max_rows + 1):
-            for cell_index in xrange(self.max_cells + 1):
+        for row_index in range(self.max_rows + 1):
+            for cell_index in range(self.max_cells + 1):
                 position = (row_index, cell_index)
                 cell = self.area[position]
                 if cell == '.':
@@ -94,7 +89,7 @@ def run_part1(file_content):
     """Implmentation for Part 1."""
     area = LumberArea(file_content)
 
-    for _ in xrange(10):
+    for _ in range(10):
         area.execute_minute()
 
     counts = area.get_counts()
@@ -108,7 +103,7 @@ def run_part2(file_content):
     cycle_index = None
     cycle_patterns = []
 
-    for minute in xrange(1000000000):
+    for minute in range(1000000000):
         area.execute_minute()
 
         pattern = str(area)

2018/day19/day19.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/19
 """
 
-from __future__ import print_function
-
 import re
 
 _IP_REGEX = re.compile(r'^#ip (\d)$')

2018/day20/day20.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/20
 """
 
-from __future__ import print_function
-
 from collections import defaultdict, deque
 from operator import itemgetter
 from sys import maxsize

2018/day21/day21.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/21
 """
 
-from __future__ import print_function
-
 import re
 
 _IP_REGEX = re.compile(r'^#ip (\d)$')

2018/day22/day22.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/22
 """
 
-from __future__ import print_function
-
 import re
 from collections import defaultdict
 from operator import itemgetter

2018/day23/day23.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/23
 """
 
-from __future__ import print_function
-
 import heapq
 import re
 from operator import attrgetter

2018/day24/day24.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/24
 """
 
-from __future__ import print_function
-
 import re
 from collections import defaultdict
 from functools import reduce

2018/day25/day25.py

@@ -4,8 +4,6 @@
 https://adventofcode.com/2018/day/25
 """
 
-from __future__ import print_function
-
 from collections import deque