fixed server bug

server/server.py

@@ -1,5 +1,10 @@
 import socket
 import ws2801
+import re
+
+def validate_data(data):
+    reg = re.compile("[0-9a-f]{6}$")
+    return reg.match(data)
 
 def start():
     host = "0.0.0.0" 
@@ -10,14 +15,18 @@ def start():
 
     # configure how many client the server can listen simultaneously
     server_socket.listen(1)
+    while True:
         conn, address = server_socket.accept()  # accept new connection
         print("Connection from: " + str(address))
-    while True:
         # receive data stream. it won't accept data packet greater than 1024 bytes
         data = conn.recv(1024).decode()
+        if not data:
+            print("Disconnected: " + str(address))
+            break
+        if validate_data(data):   
             r,g,b = ws2801.hex_to_rgb(data)
             ws2801.set_color(r,g,b)
-				
+        else:
+            print("incorrect format. use hex color code.")
     conn.close()  # close the connection
 
-start()