Use pathlib for input.txt path

day-04/day-04.py

@@ -1,4 +1,6 @@
 #!/usr/bin/python3
+from pathlib import Path
+
 
 def read_boards(input):
     boards = list()
@@ -129,8 +131,8 @@ def part_2(input):
 
 
 input = list()
-with open('input.txt') as fp:
-    input = fp.readlines()
-
-part_1(input.copy())
-part_2(input.copy())
+p = Path(__file__).with_name('input.txt')
+with open(p) as f:
+    input = f.readlines()
+    part_1(input.copy())
+    part_2(input.copy())