tests: replace pycodestyle with black

Drop pycodestyle for code style checking in favor of black. Black is
much faster, stable PEP8 compliant code style checker offering also
automatic formatting. It aims to be very stable and produce smallest
diffs. It's used by many small and big projects.

Running checkstyle with black takes a few seconds with a terse output.
Thus, test-checkstyle-diff is no longer necessary.

Expand scope of checkstyle to all python files in the repo, replacing
test-checkstyle with checkstyle-python.

Also, fixstyle-python is now available for automatic style formatting.

Note: python virtualenv has been consolidated in test/Makefile,
test/requirements*.txt which will eventually be moved to a central
location.  This is required to simply the automated generation of
docker executor images in the CI.

Type: improvement
Change-Id: I022a326603485f58585e879ac0f697fceefbc9c8
Signed-off-by: Klement Sekera <klement.sekera@gmail.com>
Signed-off-by: Dave Wallace <dwallacelf@gmail.com>

1 files changed, 173 insertions, 141 deletions

diff --git a/test/test_dhcp6.py b/test/test_dhcp6.py
index 57eb113fb13..8a00cb81f90 100644
--- a/test/test_dhcp6.py
+++ b/test/test_dhcp6.py
@@ -1,10 +1,24 @@
 from socket import AF_INET6, inet_ntop, inet_pton
 
-from scapy.layers.dhcp6 import DHCP6_Advertise, DHCP6OptClientId, \
-    DHCP6OptStatusCode, DHCP6OptPref, DHCP6OptIA_PD, DHCP6OptIAPrefix, \
-    DHCP6OptServerId, DHCP6_Solicit, DHCP6_Reply, DHCP6_Request, DHCP6_Renew, \
-    DHCP6_Rebind, DUID_LL, DHCP6_Release, DHCP6OptElapsedTime, DHCP6OptIA_NA, \
-    DHCP6OptIAAddress
+from scapy.layers.dhcp6 import (
+    DHCP6_Advertise,
+    DHCP6OptClientId,
+    DHCP6OptStatusCode,
+    DHCP6OptPref,
+    DHCP6OptIA_PD,
+    DHCP6OptIAPrefix,
+    DHCP6OptServerId,
+    DHCP6_Solicit,
+    DHCP6_Reply,
+    DHCP6_Request,
+    DHCP6_Renew,
+    DHCP6_Rebind,
+    DUID_LL,
+    DHCP6_Release,
+    DHCP6OptElapsedTime,
+    DHCP6OptIA_NA,
+    DHCP6OptIAAddress,
+)
 from scapy.layers.inet6 import IPv6, Ether, UDP
 from scapy.utils6 import in6_mactoifaceid
 
@@ -21,7 +35,7 @@ def ip6_normalize(ip6):
 
 
 class TestDHCPv6DataPlane(VppTestCase):
-    """ DHCPv6 Data Plane Test Case """
+    """DHCPv6 Data Plane Test Case"""
 
     @classmethod
     def setUpClass(cls):
@@ -49,25 +63,23 @@ class TestDHCPv6DataPlane(VppTestCase):
         super(TestDHCPv6DataPlane, self).tearDown()
 
     def test_dhcp_ia_na_send_solicit_receive_advertise(self):
-        """ Verify DHCPv6 IA NA Solicit packet and Advertise event """
+        """Verify DHCPv6 IA NA Solicit packet and Advertise event"""
 
         self.vapi.dhcp6_clients_enable_disable(enable=1)
 
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-        address = {'address': '1:2:3::5',
-                   'preferred_time': 60,
-                   'valid_time': 120}
+        address = {"address": "1:2:3::5", "preferred_time": 60, "valid_time": 120}
         self.vapi.dhcp6_send_client_message(
-            server_index=0xffffffff,
+            server_index=0xFFFFFFFF,
             mrc=1,
             msg_type=VppEnum.vl_api_dhcpv6_msg_type_t.DHCPV6_MSG_API_SOLICIT,
             sw_if_index=self.pg0.sw_if_index,
             T1=20,
             T2=40,
             addresses=[address],
-            n_addresses=len(
-                [address]))
+            n_addresses=len([address]),
+        )
         rx_list = self.pg0.get_capture(1)
         self.assertEqual(len(rx_list), 1)
         packet = rx_list[0]
@@ -89,27 +101,27 @@ class TestDHCPv6DataPlane(VppTestCase):
         self.assert_equal(ia_na.T2, 40)
         self.assert_equal(len(ia_na.ianaopts), 1)
         address = ia_na.ianaopts[0]
-        self.assert_equal(address.addr, '1:2:3::5')
+        self.assert_equal(address.addr, "1:2:3::5")
         self.assert_equal(address.preflft, 60)
         self.assert_equal(address.validlft, 120)
 
-        self.vapi.want_dhcp6_reply_events(enable_disable=1,
-                                          pid=os.getpid())
+        self.vapi.want_dhcp6_reply_events(enable_disable=1, pid=os.getpid())
 
         try:
-            ia_na_opts = DHCP6OptIAAddress(addr='7:8::2', preflft=60,
-                                           validlft=120)
-            p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-                 IPv6(src=util.mk_ll_addr(self.pg0.remote_mac),
-                      dst=self.pg0.local_ip6_ll) /
-                 UDP(sport=547, dport=546) /
-                 DHCP6_Advertise(trid=trid) /
-                 DHCP6OptServerId(duid=self.server_duid) /
-                 DHCP6OptClientId(duid=client_duid) /
-                 DHCP6OptPref(prefval=7) /
-                 DHCP6OptStatusCode(statuscode=1) /
-                 DHCP6OptIA_NA(iaid=1, T1=20, T2=40, ianaopts=ia_na_opts)
-                 )
+            ia_na_opts = DHCP6OptIAAddress(addr="7:8::2", preflft=60, validlft=120)
+            p = (
+                Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+                / IPv6(
+                    src=util.mk_ll_addr(self.pg0.remote_mac), dst=self.pg0.local_ip6_ll
+                )
+                / UDP(sport=547, dport=546)
+                / DHCP6_Advertise(trid=trid)
+                / DHCP6OptServerId(duid=self.server_duid)
+                / DHCP6OptClientId(duid=client_duid)
+                / DHCP6OptPref(prefval=7)
+                / DHCP6OptStatusCode(statuscode=1)
+                / DHCP6OptIA_NA(iaid=1, T1=20, T2=40, ianaopts=ia_na_opts)
+            )
             self.pg0.add_stream([p])
             self.pg_start()
 
@@ -123,36 +135,41 @@ class TestDHCPv6DataPlane(VppTestCase):
             reported_address = ev.addresses[0]
             address = ia_na_opts.getfieldval("addr")
             self.assert_equal(str(reported_address.address), address)
-            self.assert_equal(reported_address.preferred_time,
-                              ia_na_opts.getfieldval("preflft"))
-            self.assert_equal(reported_address.valid_time,
-                              ia_na_opts.getfieldval("validlft"))
+            self.assert_equal(
+                reported_address.preferred_time, ia_na_opts.getfieldval("preflft")
+            )
+            self.assert_equal(
+                reported_address.valid_time, ia_na_opts.getfieldval("validlft")
+            )
 
         finally:
             self.vapi.want_dhcp6_reply_events(enable_disable=0)
         self.vapi.dhcp6_clients_enable_disable(enable=0)
 
     def test_dhcp_pd_send_solicit_receive_advertise(self):
-        """ Verify DHCPv6 PD Solicit packet and Advertise event """
+        """Verify DHCPv6 PD Solicit packet and Advertise event"""
 
         self.vapi.dhcp6_clients_enable_disable(enable=1)
 
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
 
-        prefix = {'prefix': {'address': '1:2:3::', 'len': 50},
-                  'preferred_time': 60,
-                  'valid_time': 120}
+        prefix = {
+            "prefix": {"address": "1:2:3::", "len": 50},
+            "preferred_time": 60,
+            "valid_time": 120,
+        }
         prefixes = [prefix]
         self.vapi.dhcp6_pd_send_client_message(
-            server_index=0xffffffff,
+            server_index=0xFFFFFFFF,
             mrc=1,
             msg_type=VppEnum.vl_api_dhcpv6_msg_type_t.DHCPV6_MSG_API_SOLICIT,
             sw_if_index=self.pg0.sw_if_index,
             T1=20,
             T2=40,
             prefixes=prefixes,
-            n_prefixes=len(prefixes))
+            n_prefixes=len(prefixes),
+        )
         rx_list = self.pg0.get_capture(1)
         self.assertEqual(len(rx_list), 1)
         packet = rx_list[0]
@@ -174,28 +191,30 @@ class TestDHCPv6DataPlane(VppTestCase):
         self.assert_equal(ia_pd.T2, 40)
         self.assert_equal(len(ia_pd.iapdopt), 1)
         prefix = ia_pd.iapdopt[0]
-        self.assert_equal(prefix.prefix, '1:2:3::')
+        self.assert_equal(prefix.prefix, "1:2:3::")
         self.assert_equal(prefix.plen, 50)
         self.assert_equal(prefix.preflft, 60)
         self.assert_equal(prefix.validlft, 120)
 
-        self.vapi.want_dhcp6_pd_reply_events(enable_disable=1,
-                                             pid=os.getpid())
+        self.vapi.want_dhcp6_pd_reply_events(enable_disable=1, pid=os.getpid())
 
         try:
-            ia_pd_opts = DHCP6OptIAPrefix(prefix='7:8::', plen=56, preflft=60,
-                                          validlft=120)
-            p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-                 IPv6(src=util.mk_ll_addr(self.pg0.remote_mac),
-                      dst=self.pg0.local_ip6_ll) /
-                 UDP(sport=547, dport=546) /
-                 DHCP6_Advertise(trid=trid) /
-                 DHCP6OptServerId(duid=self.server_duid) /
-                 DHCP6OptClientId(duid=client_duid) /
-                 DHCP6OptPref(prefval=7) /
-                 DHCP6OptStatusCode(statuscode=1) /
-                 DHCP6OptIA_PD(iaid=1, T1=20, T2=40, iapdopt=ia_pd_opts)
-                 )
+            ia_pd_opts = DHCP6OptIAPrefix(
+                prefix="7:8::", plen=56, preflft=60, validlft=120
+            )
+            p = (
+                Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+                / IPv6(
+                    src=util.mk_ll_addr(self.pg0.remote_mac), dst=self.pg0.local_ip6_ll
+                )
+                / UDP(sport=547, dport=546)
+                / DHCP6_Advertise(trid=trid)
+                / DHCP6OptServerId(duid=self.server_duid)
+                / DHCP6OptClientId(duid=client_duid)
+                / DHCP6OptPref(prefval=7)
+                / DHCP6OptStatusCode(statuscode=1)
+                / DHCP6OptIA_PD(iaid=1, T1=20, T2=40, iapdopt=ia_pd_opts)
+            )
             self.pg0.add_stream([p])
             self.pg_start()
 
@@ -208,14 +227,17 @@ class TestDHCPv6DataPlane(VppTestCase):
 
             reported_prefix = ev.prefixes[0]
             prefix = ia_pd_opts.getfieldval("prefix")
+            self.assert_equal(str(reported_prefix.prefix).split("/")[0], prefix)
+            self.assert_equal(
+                int(str(reported_prefix.prefix).split("/")[1]),
+                ia_pd_opts.getfieldval("plen"),
+            )
             self.assert_equal(
-                str(reported_prefix.prefix).split('/')[0], prefix)
-            self.assert_equal(int(str(reported_prefix.prefix).split('/')[1]),
-                              ia_pd_opts.getfieldval("plen"))
-            self.assert_equal(reported_prefix.preferred_time,
-                              ia_pd_opts.getfieldval("preflft"))
-            self.assert_equal(reported_prefix.valid_time,
-                              ia_pd_opts.getfieldval("validlft"))
+                reported_prefix.preferred_time, ia_pd_opts.getfieldval("preflft")
+            )
+            self.assert_equal(
+                reported_prefix.valid_time, ia_pd_opts.getfieldval("validlft")
+            )
 
         finally:
             self.vapi.want_dhcp6_pd_reply_events(enable_disable=0)
@@ -224,7 +246,7 @@ class TestDHCPv6DataPlane(VppTestCase):
 
 @tag_run_solo
 class TestDHCPv6IANAControlPlane(VppTestCase):
-    """ DHCPv6 IA NA Control Plane Test Case """
+    """DHCPv6 IA NA Control Plane Test Case"""
 
     @classmethod
     def setUpClass(cls):
@@ -248,18 +270,19 @@ class TestDHCPv6IANAControlPlane(VppTestCase):
         self.T2 = 2
 
         fib = self.vapi.ip_route_dump(0, True)
-        self.initial_addresses = set(self.get_interface_addresses(fib,
-                                                                  self.pg0))
+        self.initial_addresses = set(self.get_interface_addresses(fib, self.pg0))
 
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
 
-        self.vapi.dhcp6_client_enable_disable(sw_if_index=self.pg0.sw_if_index,
-                                              enable=1)
+        self.vapi.dhcp6_client_enable_disable(
+            sw_if_index=self.pg0.sw_if_index, enable=1
+        )
 
     def tearDown(self):
-        self.vapi.dhcp6_client_enable_disable(sw_if_index=self.pg0.sw_if_index,
-                                              enable=0)
+        self.vapi.dhcp6_client_enable_disable(
+            sw_if_index=self.pg0.sw_if_index, enable=0
+        )
 
         for i in self.interfaces:
             i.admin_down()
@@ -302,12 +325,12 @@ class TestDHCPv6IANAControlPlane(VppTestCase):
                 self.trid = packet[msg_type].trid
             ip = packet[IPv6]
             udp = packet[UDP]
-            self.assertEqual(ip.dst, 'ff02::1:2')
+            self.assertEqual(ip.dst, "ff02::1:2")
             self.assertEqual(udp.sport, 546)
             self.assertEqual(udp.dport, 547)
             dhcpv6 = packet[msg_type]
             elapsed_time = dhcpv6[DHCP6OptElapsedTime]
-            if (is_resend):
+            if is_resend:
                 self.assertNotEqual(elapsed_time.elapsedtime, 0)
             else:
                 self.assertEqual(elapsed_time.elapsedtime, 0)
@@ -346,15 +369,15 @@ class TestDHCPv6IANAControlPlane(VppTestCase):
             opt_ia_na = DHCP6OptIA_NA(iaid=1, T1=t1, T2=t2)
         else:
             opt_ia_na = DHCP6OptIA_NA(iaid=1, T1=t1, T2=t2, ianaopts=ianaopts)
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IPv6(src=util.mk_ll_addr(self.pg0.remote_mac),
-                  dst=self.pg0.local_ip6_ll) /
-             UDP(sport=547, dport=546) /
-             msg_type(trid=self.trid) /
-             DHCP6OptServerId(duid=self.server_duid) /
-             DHCP6OptClientId(duid=self.client_duid) /
-             opt_ia_na
-             )
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IPv6(src=util.mk_ll_addr(self.pg0.remote_mac), dst=self.pg0.local_ip6_ll)
+            / UDP(sport=547, dport=546)
+            / msg_type(trid=self.trid)
+            / DHCP6OptServerId(duid=self.server_duid)
+            / DHCP6OptClientId(duid=self.client_duid)
+            / opt_ia_na
+        )
         self.pg0.add_stream([p])
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -366,7 +389,7 @@ class TestDHCPv6IANAControlPlane(VppTestCase):
         self.send_packet(DHCP6_Reply, t1, t2, ianaopts)
 
     def test_T1_and_T2_timeouts(self):
-        """ Test T1 and T2 timeouts """
+        """Test T1 and T2 timeouts"""
 
         self.wait_for_solicit()
         self.send_advertise()
@@ -384,10 +407,9 @@ class TestDHCPv6IANAControlPlane(VppTestCase):
         self.wait_for_rebind()
 
     def test_addresses(self):
-        """ Test handling of addresses """
+        """Test handling of addresses"""
 
-        ia_na_opts = DHCP6OptIAAddress(addr='7:8::2', preflft=1,
-                                       validlft=2)
+        ia_na_opts = DHCP6OptIAAddress(addr="7:8::2", preflft=1, validlft=2)
 
         self.wait_for_solicit()
         self.send_advertise(t1=20, t2=40, ianaopts=ia_na_opts)
@@ -399,7 +421,7 @@ class TestDHCPv6IANAControlPlane(VppTestCase):
         new_addresses = self.get_addresses()
         self.assertEqual(len(new_addresses), 1)
         addr = list(new_addresses)[0]
-        self.assertEqual(addr, '7:8::2')
+        self.assertEqual(addr, "7:8::2")
 
         self.sleep(2)
 
@@ -410,7 +432,7 @@ class TestDHCPv6IANAControlPlane(VppTestCase):
         self.assertEqual(len(new_addresses), 0)
 
     def test_sending_client_messages_solicit(self):
-        """ VPP receives messages from DHCPv6 client """
+        """VPP receives messages from DHCPv6 client"""
 
         self.wait_for_solicit()
         self.send_packet(DHCP6_Solicit)
@@ -421,7 +443,7 @@ class TestDHCPv6IANAControlPlane(VppTestCase):
         self.wait_for_solicit(is_resend=True)
 
     def test_sending_inappropriate_packets(self):
-        """ Server sends messages with inappropriate message types """
+        """Server sends messages with inappropriate message types"""
 
         self.wait_for_solicit()
         self.send_reply()
@@ -434,7 +456,7 @@ class TestDHCPv6IANAControlPlane(VppTestCase):
         self.wait_for_renew()
 
     def test_no_address_available_in_advertise(self):
-        """ Advertise message contains NoAddrsAvail status code """
+        """Advertise message contains NoAddrsAvail status code"""
 
         self.wait_for_solicit()
         noavail = DHCP6OptStatusCode(statuscode=2)  # NoAddrsAvail
@@ -442,12 +464,12 @@ class TestDHCPv6IANAControlPlane(VppTestCase):
         self.wait_for_solicit(is_resend=True)
 
     def test_preferred_greater_than_valid_lifetime(self):
-        """ Preferred lifetime is greater than valid lifetime """
+        """Preferred lifetime is greater than valid lifetime"""
 
         self.wait_for_solicit()
         self.send_advertise()
         self.wait_for_request()
-        ia_na_opts = DHCP6OptIAAddress(addr='7:8::2', preflft=4, validlft=3)
+        ia_na_opts = DHCP6OptIAAddress(addr="7:8::2", preflft=4, validlft=3)
         self.send_reply(ianaopts=ia_na_opts)
 
         self.sleep(0.5)
@@ -459,12 +481,12 @@ class TestDHCPv6IANAControlPlane(VppTestCase):
         self.assertEqual(len(new_addresses), 0)
 
     def test_T1_greater_than_T2(self):
-        """ T1 is greater than T2 """
+        """T1 is greater than T2"""
 
         self.wait_for_solicit()
         self.send_advertise()
         self.wait_for_request()
-        ia_na_opts = DHCP6OptIAAddress(addr='7:8::2', preflft=4, validlft=8)
+        ia_na_opts = DHCP6OptIAAddress(addr="7:8::2", preflft=4, validlft=8)
         self.send_reply(t1=80, t2=40, ianaopts=ia_na_opts)
 
         self.sleep(0.5)
@@ -478,7 +500,7 @@ class TestDHCPv6IANAControlPlane(VppTestCase):
 
 @tag_fixme_vpp_workers
 class TestDHCPv6PDControlPlane(VppTestCase):
-    """ DHCPv6 PD Control Plane Test Case """
+    """DHCPv6 PD Control Plane Test Case"""
 
     @classmethod
     def setUpClass(cls):
@@ -502,22 +524,19 @@ class TestDHCPv6PDControlPlane(VppTestCase):
         self.T2 = 2
 
         fib = self.vapi.ip_route_dump(0, True)
-        self.initial_addresses = set(self.get_interface_addresses(fib,
-                                                                  self.pg1))
+        self.initial_addresses = set(self.get_interface_addresses(fib, self.pg1))
 
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
 
-        self.prefix_group = 'my-pd-prefix-group'
+        self.prefix_group = "my-pd-prefix-group"
 
         self.vapi.dhcp6_pd_client_enable_disable(
-            enable=1,
-            sw_if_index=self.pg0.sw_if_index,
-            prefix_group=self.prefix_group)
+            enable=1, sw_if_index=self.pg0.sw_if_index, prefix_group=self.prefix_group
+        )
 
     def tearDown(self):
-        self.vapi.dhcp6_pd_client_enable_disable(self.pg0.sw_if_index,
-                                                 enable=0)
+        self.vapi.dhcp6_pd_client_enable_disable(self.pg0.sw_if_index, enable=0)
 
         for i in self.interfaces:
             i.admin_down()
@@ -560,12 +579,12 @@ class TestDHCPv6PDControlPlane(VppTestCase):
                 self.trid = packet[msg_type].trid
             ip = packet[IPv6]
             udp = packet[UDP]
-            self.assertEqual(ip.dst, 'ff02::1:2')
+            self.assertEqual(ip.dst, "ff02::1:2")
             self.assertEqual(udp.sport, 546)
             self.assertEqual(udp.dport, 547)
             dhcpv6 = packet[msg_type]
             elapsed_time = dhcpv6[DHCP6OptElapsedTime]
-            if (is_resend):
+            if is_resend:
                 self.assertNotEqual(elapsed_time.elapsedtime, 0)
             else:
                 self.assertEqual(elapsed_time.elapsedtime, 0)
@@ -604,15 +623,15 @@ class TestDHCPv6PDControlPlane(VppTestCase):
             opt_ia_pd = DHCP6OptIA_PD(iaid=1, T1=t1, T2=t2)
         else:
             opt_ia_pd = DHCP6OptIA_PD(iaid=1, T1=t1, T2=t2, iapdopt=iapdopt)
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IPv6(src=util.mk_ll_addr(self.pg0.remote_mac),
-                  dst=self.pg0.local_ip6_ll) /
-             UDP(sport=547, dport=546) /
-             msg_type(trid=self.trid) /
-             DHCP6OptServerId(duid=self.server_duid) /
-             DHCP6OptClientId(duid=self.client_duid) /
-             opt_ia_pd
-             )
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IPv6(src=util.mk_ll_addr(self.pg0.remote_mac), dst=self.pg0.local_ip6_ll)
+            / UDP(sport=547, dport=546)
+            / msg_type(trid=self.trid)
+            / DHCP6OptServerId(duid=self.server_duid)
+            / DHCP6OptClientId(duid=self.client_duid)
+            / opt_ia_pd
+        )
         self.pg0.add_stream([p])
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -624,7 +643,7 @@ class TestDHCPv6PDControlPlane(VppTestCase):
         self.send_packet(DHCP6_Reply, t1, t2, iapdopt)
 
     def test_T1_and_T2_timeouts(self):
-        """ Test T1 and T2 timeouts """
+        """Test T1 and T2 timeouts"""
 
         self.wait_for_solicit()
         self.send_advertise()
@@ -642,18 +661,20 @@ class TestDHCPv6PDControlPlane(VppTestCase):
         self.wait_for_rebind()
 
     def test_prefixes(self):
-        """ Test handling of prefixes """
+        """Test handling of prefixes"""
 
-        address1 = '::2:0:0:0:405/60'
-        address2 = '::76:0:0:0:406/62'
+        address1 = "::2:0:0:0:405/60"
+        address2 = "::76:0:0:0:406/62"
         try:
             self.vapi.ip6_add_del_address_using_prefix(
                 sw_if_index=self.pg1.sw_if_index,
                 address_with_prefix=address1,
-                prefix_group=self.prefix_group)
+                prefix_group=self.prefix_group,
+            )
 
-            ia_pd_opts = DHCP6OptIAPrefix(prefix='7:8::', plen=56, preflft=2,
-                                          validlft=3)
+            ia_pd_opts = DHCP6OptIAPrefix(
+                prefix="7:8::", plen=56, preflft=2, validlft=3
+            )
 
             self.wait_for_solicit()
             self.send_advertise(t1=20, t2=40, iapdopt=ia_pd_opts)
@@ -665,14 +686,15 @@ class TestDHCPv6PDControlPlane(VppTestCase):
             new_addresses = self.get_addresses()
             self.assertEqual(len(new_addresses), 1)
             addr = list(new_addresses)[0]
-            self.assertEqual(addr, '7:8:0:2::405')
+            self.assertEqual(addr, "7:8:0:2::405")
 
             self.sleep(1)
 
             self.vapi.ip6_add_del_address_using_prefix(
                 sw_if_index=self.pg1.sw_if_index,
                 address_with_prefix=address2,
-                prefix_group=self.prefix_group)
+                prefix_group=self.prefix_group,
+            )
 
             self.sleep(1)
 
@@ -683,10 +705,10 @@ class TestDHCPv6PDControlPlane(VppTestCase):
             self.assertEqual(len(new_addresses), 2)
             addr1 = list(new_addresses)[0]
             addr2 = list(new_addresses)[1]
-            if addr1 == '7:8:0:76::406':
+            if addr1 == "7:8:0:76::406":
                 addr1, addr2 = addr2, addr1
-            self.assertEqual(addr1, '7:8:0:2::405')
-            self.assertEqual(addr2, '7:8:0:76::406')
+            self.assertEqual(addr1, "7:8:0:2::405")
+            self.assertEqual(addr2, "7:8:0:76::406")
 
             self.sleep(1)
 
@@ -701,15 +723,19 @@ class TestDHCPv6PDControlPlane(VppTestCase):
                 self.vapi.ip6_add_del_address_using_prefix(
                     sw_if_index=self.pg1.sw_if_index,
                     address_with_prefix=address1,
-                    prefix_group=self.prefix_group, is_add=0)
+                    prefix_group=self.prefix_group,
+                    is_add=0,
+                )
             if address2 is not None:
                 self.vapi.ip6_add_del_address_using_prefix(
                     sw_if_index=self.pg1.sw_if_index,
                     address_with_prefix=address2,
-                    prefix_group=self.prefix_group, is_add=0)
+                    prefix_group=self.prefix_group,
+                    is_add=0,
+                )
 
     def test_sending_client_messages_solicit(self):
-        """ VPP receives messages from DHCPv6 client """
+        """VPP receives messages from DHCPv6 client"""
 
         self.wait_for_solicit()
         self.send_packet(DHCP6_Solicit)
@@ -720,7 +746,7 @@ class TestDHCPv6PDControlPlane(VppTestCase):
         self.wait_for_solicit(is_resend=True)
 
     def test_sending_inappropriate_packets(self):
-        """ Server sends messages with inappropriate message types """
+        """Server sends messages with inappropriate message types"""
 
         self.wait_for_solicit()
         self.send_reply()
@@ -733,7 +759,7 @@ class TestDHCPv6PDControlPlane(VppTestCase):
         self.wait_for_renew()
 
     def test_no_prefix_available_in_advertise(self):
-        """ Advertise message contains NoPrefixAvail status code """
+        """Advertise message contains NoPrefixAvail status code"""
 
         self.wait_for_solicit()
         noavail = DHCP6OptStatusCode(statuscode=6)  # NoPrefixAvail
@@ -741,20 +767,22 @@ class TestDHCPv6PDControlPlane(VppTestCase):
         self.wait_for_solicit(is_resend=True)
 
     def test_preferred_greater_than_valid_lifetime(self):
-        """ Preferred lifetime is greater than valid lifetime """
+        """Preferred lifetime is greater than valid lifetime"""
 
-        address1 = '::2:0:0:0:405/60'
+        address1 = "::2:0:0:0:405/60"
         try:
             self.vapi.ip6_add_del_address_using_prefix(
                 sw_if_index=self.pg1.sw_if_index,
                 address_with_prefix=address1,
-                prefix_group=self.prefix_group)
+                prefix_group=self.prefix_group,
+            )
 
             self.wait_for_solicit()
             self.send_advertise()
             self.wait_for_request()
-            ia_pd_opts = DHCP6OptIAPrefix(prefix='7:8::', plen=56, preflft=4,
-                                          validlft=3)
+            ia_pd_opts = DHCP6OptIAPrefix(
+                prefix="7:8::", plen=56, preflft=4, validlft=3
+            )
             self.send_reply(iapdopt=ia_pd_opts)
 
             self.sleep(0.5)
@@ -770,23 +798,26 @@ class TestDHCPv6PDControlPlane(VppTestCase):
                 sw_if_index=self.pg1.sw_if_index,
                 address_with_prefix=address1,
                 prefix_group=self.prefix_group,
-                is_add=0)
+                is_add=0,
+            )
 
     def test_T1_greater_than_T2(self):
-        """ T1 is greater than T2 """
+        """T1 is greater than T2"""
 
-        address1 = '::2:0:0:0:405/60'
+        address1 = "::2:0:0:0:405/60"
         try:
             self.vapi.ip6_add_del_address_using_prefix(
                 sw_if_index=self.pg1.sw_if_index,
                 address_with_prefix=address1,
-                prefix_group=self.prefix_group)
+                prefix_group=self.prefix_group,
+            )
 
             self.wait_for_solicit()
             self.send_advertise()
             self.wait_for_request()
-            ia_pd_opts = DHCP6OptIAPrefix(prefix='7:8::', plen=56, preflft=4,
-                                          validlft=8)
+            ia_pd_opts = DHCP6OptIAPrefix(
+                prefix="7:8::", plen=56, preflft=4, validlft=8
+            )
             self.send_reply(t1=80, t2=40, iapdopt=ia_pd_opts)
 
             self.sleep(0.5)
@@ -802,4 +833,5 @@ class TestDHCPv6PDControlPlane(VppTestCase):
                 sw_if_index=self.pg1.sw_if_index,
                 prefix_group=self.prefix_group,
                 address_with_prefix=address1,
-                is_add=False)
+                is_add=False,
+            )