Made it not crash if the class contains functions.

data_file.py

@@ -1,5 +1,6 @@
 #!/usr/bin/python3
 
+import os
 import json
 
 
@@ -102,15 +103,20 @@ class DataclassJSONFile:
 
 # these 2 functions do the exact same thing as in the class above
 def load_dataclass_json(dataclass, file_path: str):
+    if os.path.exists(file_path):
         file = open(file_path, "r")
         class_dict = json.load(file)
         file.close()
 
+    else:
+        class_dict = {}
+
     return dataclass(**class_dict)
 
 
 def save_dataclass_json(class_instance, file_path: str):
     class_dict = class_instance.__dict__
+    class_dict = dict(filter(lambda pair: not callable(pair[1]), class_dict.items()))
 
     file = open(file_path, "w")
     json.dump(class_dict, file)