update: refactor codes

model/command/parser.py

@@ -0,0 +1,19 @@
+class CommandTokens():
+    def __init__(self) -> None:
+        self.tokens = []
+        self.len = 0
+        
+    def get(self, idx: int):
+        if idx >= self.len:
+            return None
+        return self.tokens[idx].strip()
+
+class CommandParser():
+    def __init__(self):
+        pass
+        
+    def parse(self, message: str):
+        cmd_tokens = CommandTokens()
+        cmd_tokens.tokens = message.split(" ")
+        cmd_tokens.len = len(cmd_tokens.tokens)
+        return cmd_tokens