commit rest of old client/server fixes

helpers.py

@@ -1,7 +1,19 @@
+import json
+
 HEADER_LENGTH = 10
 
 
-def prepare(message: str, encoding='ascii') -> bytes:
+def prepare(message: str, encoding='utf-8') -> bytes:
     """Prepares a message for sending through a socket by adding a proper header and encoding it."""
     header = f'{len(message):<{HEADER_LENGTH}}'
     return (header + message).encode(encoding)
+
+
+def prepare_json(object) -> bytes:
+    """
+    Prepares a object for sending as encoded JSON with a header.
+
+    :param object: A JSON-encodable object
+    :return: Encoded JSON
+    """
+    return prepare(json.dumps(object))