fix: add explicit encoding to open() calls for cross-platform portability

Python's open() uses locale-dependent encoding by default, which varies
across platforms (UTF-8 on macOS/Linux, cp1252 on Windows). This causes
files to be read/written incorrectly on some systems.

Added encoding='utf-8' to all text-mode open() calls in:
- searches/tabu_search.py
- data_structures/arrays/sudoku_solver.py
- strings/word_patterns.py
- data_compression/huffman.py
- strings/detecting_english_programmatically.py

Author: Niki

data_compression/huffman.py

@@ -26,7 +26,7 @@ def parse_file(file_path: str) -> list[Letter]:
     frequencies, then convert the dict into a list of Letters.
     """
     chars: dict[str, int] = {}
-    with open(file_path) as f:
+    with open(file_path, encoding="utf-8") as f:
         while True:
             c = f.read(1)
             if not c:
@@ -78,7 +78,7 @@ def huffman(file_path: str) -> None:
         k: v for letter in traverse_tree(root, "") for k, v in letter.bitstring.items()
     }
     print(f"Huffman Coding  of {file_path}: ")
-    with open(file_path) as f:
+    with open(file_path, encoding="utf-8") as f:
         while True:
             c = f.read(1)
             if not c:

data_structures/arrays/sudoku_solver.py

@@ -206,7 +206,7 @@ def unitsolved(unit):
 
 def from_file(filename, sep="\n"):
     "Parse a file into a list of strings, separated by sep."
-    with open(filename) as file:
+    with open(filename, encoding="utf-8") as file:
         return file.read().strip().split(sep)
 
 

searches/tabu_search.py

@@ -49,7 +49,7 @@ def generate_neighbours(path):
 
     dict_of_neighbours = {}
 
-    with open(path) as f:
+    with open(path, encoding="utf-8") as f:
         for line in f:
             if line.split()[0] not in dict_of_neighbours:
                 _list = []
@@ -88,7 +88,7 @@ def generate_first_solution(path, dict_of_neighbours):
         will travel, if he follows the path in first_solution.
     """
 
-    with open(path) as f:
+    with open(path, encoding="utf-8") as f:
         start_node = f.read(1)
     end_node = start_node
 

strings/detecting_english_programmatically.py

@@ -7,7 +7,7 @@
 def load_dictionary() -> dict[str, None]:
     path = os.path.split(os.path.realpath(__file__))
     english_words: dict[str, None] = {}
-    with open(path[0] + "/dictionary.txt") as dictionary_file:
+    with open(path[0] + "/dictionary.txt", encoding="utf-8") as dictionary_file:
         for word in dictionary_file.read().split("\n"):
             english_words[word] = None
     return english_words

strings/word_patterns.py

@@ -46,7 +46,7 @@ def get_word_pattern(word: str) -> str:
     import time
 
     start_time = time.time()
-    with open("dictionary.txt") as in_file:
+    with open("dictionary.txt", encoding="utf-8") as in_file:
         word_list = in_file.read().splitlines()
 
     all_patterns: dict = {}