diff --git a/examples/network/udp_multicast_client.py b/examples/network/udp_multicast_client.py
index 9de2241c7b79f..d7d12e01a6215 100755
--- a/examples/network/udp_multicast_client.py
+++ b/examples/network/udp_multicast_client.py
@@ -8,7 +8,8 @@
 PASSWORD = "PASSWORD"
 
 wlan = network.WLAN(network.STA_IF)
-wlan.ifconfig(("172.16.55.55", "255.255.255.0", "172.16.55.1", "172.16.55.1"))  # class B network
+# class B network
+wlan.ifconfig(("172.16.55.55", "255.255.255.0", "172.16.55.1", "172.16.55.1"))
 wlan.active(True)
 wlan.connect(SSID, PASSWORD)
 while not wlan.isconnected():
@@ -21,6 +22,7 @@
 def inet_aton(str_addr):
     return bytes(map(int, str_addr.split(".")))
 
+
 # TIMEOUT = None  # block
 # TIMEOUT = 5  # seconds
 TIMEOUT = 0  # non blocking
@@ -38,7 +40,7 @@ def inet_aton(str_addr):
 skt.setsockopt(
     socket.IPPROTO_IP,
     socket.IP_ADD_MEMBERSHIP,
-    struct.pack(">4s4s", inet_aton(MULTICAST_IP), inet_aton(client_ip))
+    struct.pack(">4s4s", inet_aton(MULTICAST_IP), inet_aton(client_ip)),
 )  # join to the multicast address
 skt.bind(sockaddr)  # not skt.connect(sockaddr)
 skt.settimeout(TIMEOUT)
diff --git a/examples/network/udp_multicast_server.py b/examples/network/udp_multicast_server.py
index aadb462690303..ffdb756e0c7fe 100755
--- a/examples/network/udp_multicast_server.py
+++ b/examples/network/udp_multicast_server.py
@@ -8,7 +8,8 @@
 PASSWORD = "PASSWORD"
 
 wlan = network.WLAN(network.STA_IF)
-wlan.ifconfig(("192.168.44.44", "255.255.255.0", "192.168.44.1", "192.168.44.1"))  # class C network
+# class C network
+wlan.ifconfig(("192.168.44.44", "255.255.255.0", "192.168.44.1", "192.168.44.1"))
 wlan.active(True)
 wlan.connect(SSID, PASSWORD)
 while not wlan.isconnected():
@@ -21,6 +22,7 @@
 def inet_aton(str_addr):
     return bytes(map(int, str_addr.split(".")))
 
+
 # TIMEOUT = None  # block
 # TIMEOUT = 5  # seconds
 TIMEOUT = 0  # non blocking
@@ -38,7 +40,7 @@ def inet_aton(str_addr):
 skt.setsockopt(
     socket.IPPROTO_IP,
     socket.IP_ADD_MEMBERSHIP,
-    struct.pack(">4s4s", inet_aton(MULTICAST_IP), inet_aton(server_ip))
+    struct.pack(">4s4s", inet_aton(MULTICAST_IP), inet_aton(server_ip)),
 )  # join to the multicast address
 skt.bind(sockaddr)
 skt.settimeout(TIMEOUT)