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>

13 files changed, 299 insertions, 215 deletions

diff --git a/src/plugins/nat/extras/nat_100ks.py b/src/plugins/nat/extras/nat_100ks.py
index c85a4591cd3..4e8dc2486d6 100644
--- a/src/plugins/nat/extras/nat_100ks.py
+++ b/src/plugins/nat/extras/nat_100ks.py
@@ -1,35 +1,39 @@
 from trex_stl_lib.api import *
 
-class STLS1:
 
-    def create_stream (self):
-        base_pkt = Ether()/IP(dst="2.2.0.1")/UDP(dport=12)
+class STLS1:
+    def create_stream(self):
+        base_pkt = Ether() / IP(dst="2.2.0.1") / UDP(dport=12)
 
         pad = Padding()
         if len(base_pkt) < 64:
             pad_len = 64 - len(base_pkt)
-            pad.load = '\x00' * pad_len
+            pad.load = "\x00" * pad_len
 
         vm = STLVM()
 
-        vm.tuple_var(name="tuple", ip_min="10.0.0.3", ip_max="10.0.3.234", port_min=1025, port_max=1124, limit_flows = 100000)
+        vm.tuple_var(
+            name="tuple",
+            ip_min="10.0.0.3",
+            ip_max="10.0.3.234",
+            port_min=1025,
+            port_max=1124,
+            limit_flows=100000,
+        )
 
         vm.write(fv_name="tuple.ip", pkt_offset="IP.src")
         vm.fix_chksum()
 
         vm.write(fv_name="tuple.port", pkt_offset="UDP.sport")
 
-        pkt = STLPktBuilder(pkt=base_pkt/pad, vm=vm)
+        pkt = STLPktBuilder(pkt=base_pkt / pad, vm=vm)
 
         return STLStream(packet=pkt, mode=STLTXCont())
 
-    def get_streams (self, direction = 0, **kwargs):
+    def get_streams(self, direction=0, **kwargs):
         return [self.create_stream()]
 
 
 # dynamic load - used for trex console or simulator
 def register():
     return STLS1()
-
-
-
diff --git a/src/plugins/nat/extras/nat_10Ms.py b/src/plugins/nat/extras/nat_10Ms.py
index 6ce62a0b5e7..96a18ec018a 100644
--- a/src/plugins/nat/extras/nat_10Ms.py
+++ b/src/plugins/nat/extras/nat_10Ms.py
@@ -1,35 +1,39 @@
 from trex_stl_lib.api import *
 
-class STLS1:
 
-    def create_stream (self):
-        base_pkt = Ether()/IP(dst="2.2.0.1")/UDP(dport=12)
+class STLS1:
+    def create_stream(self):
+        base_pkt = Ether() / IP(dst="2.2.0.1") / UDP(dport=12)
 
         pad = Padding()
         if len(base_pkt) < 64:
             pad_len = 64 - len(base_pkt)
-            pad.load = '\x00' * pad_len
+            pad.load = "\x00" * pad_len
 
         vm = STLVM()
 
-        vm.tuple_var(name="tuple", ip_min="10.0.0.3", ip_max="10.1.134.162", port_min=1025, port_max=1124, limit_flows=10000000)
+        vm.tuple_var(
+            name="tuple",
+            ip_min="10.0.0.3",
+            ip_max="10.1.134.162",
+            port_min=1025,
+            port_max=1124,
+            limit_flows=10000000,
+        )
 
         vm.write(fv_name="tuple.ip", pkt_offset="IP.src")
         vm.fix_chksum()
 
         vm.write(fv_name="tuple.port", pkt_offset="UDP.sport")
 
-        pkt = STLPktBuilder(pkt=base_pkt/pad, vm=vm)
+        pkt = STLPktBuilder(pkt=base_pkt / pad, vm=vm)
 
         return STLStream(packet=pkt, mode=STLTXCont())
 
-    def get_streams (self, direction = 0, **kwargs):
+    def get_streams(self, direction=0, **kwargs):
         return [self.create_stream()]
 
 
 # dynamic load - used for trex console or simulator
 def register():
     return STLS1()
-
-
-
diff --git a/src/plugins/nat/extras/nat_10ks.py b/src/plugins/nat/extras/nat_10ks.py
index 33c7196eb9e..c210d5e81d8 100644
--- a/src/plugins/nat/extras/nat_10ks.py
+++ b/src/plugins/nat/extras/nat_10ks.py
@@ -1,35 +1,39 @@
 from trex_stl_lib.api import *
 
-class STLS1:
 
-    def create_stream (self):
-        base_pkt = Ether()/IP(dst="2.2.0.1")/UDP(dport=12)
+class STLS1:
+    def create_stream(self):
+        base_pkt = Ether() / IP(dst="2.2.0.1") / UDP(dport=12)
 
         pad = Padding()
         if len(base_pkt) < 64:
             pad_len = 64 - len(base_pkt)
-            pad.load = '\x00' * pad_len
+            pad.load = "\x00" * pad_len
 
         vm = STLVM()
 
-        vm.tuple_var(name="tuple", ip_min="10.0.0.3", ip_max="10.0.0.102", port_min=1025, port_max=1124, limit_flows = 10000)
+        vm.tuple_var(
+            name="tuple",
+            ip_min="10.0.0.3",
+            ip_max="10.0.0.102",
+            port_min=1025,
+            port_max=1124,
+            limit_flows=10000,
+        )
 
         vm.write(fv_name="tuple.ip", pkt_offset="IP.src")
         vm.fix_chksum()
 
         vm.write(fv_name="tuple.port", pkt_offset="UDP.sport")
 
-        pkt = STLPktBuilder(pkt=base_pkt/pad, vm=vm)
+        pkt = STLPktBuilder(pkt=base_pkt / pad, vm=vm)
 
         return STLStream(packet=pkt, mode=STLTXCont())
 
-    def get_streams (self, direction = 0, **kwargs):
+    def get_streams(self, direction=0, **kwargs):
         return [self.create_stream()]
 
 
 # dynamic load - used for trex console or simulator
 def register():
     return STLS1()
-
-
-
diff --git a/src/plugins/nat/extras/nat_1Ms.py b/src/plugins/nat/extras/nat_1Ms.py
index 73a91a70985..7271cf73781 100644
--- a/src/plugins/nat/extras/nat_1Ms.py
+++ b/src/plugins/nat/extras/nat_1Ms.py
@@ -1,35 +1,39 @@
 from trex_stl_lib.api import *
 
-class STLS1:
 
-    def create_stream (self):
-        base_pkt = Ether()/IP(dst="2.2.0.1")/UDP(dport=12)
+class STLS1:
+    def create_stream(self):
+        base_pkt = Ether() / IP(dst="2.2.0.1") / UDP(dport=12)
 
         pad = Padding()
         if len(base_pkt) < 64:
             pad_len = 64 - len(base_pkt)
-            pad.load = '\x00' * pad_len
+            pad.load = "\x00" * pad_len
 
         vm = STLVM()
 
-        vm.tuple_var(name="tuple", ip_min="10.0.0.3", ip_max="10.0.39.18", port_min=1025, port_max=1124, limit_flows = 1000000)
+        vm.tuple_var(
+            name="tuple",
+            ip_min="10.0.0.3",
+            ip_max="10.0.39.18",
+            port_min=1025,
+            port_max=1124,
+            limit_flows=1000000,
+        )
 
         vm.write(fv_name="tuple.ip", pkt_offset="IP.src")
         vm.fix_chksum()
 
         vm.write(fv_name="tuple.port", pkt_offset="UDP.sport")
 
-        pkt = STLPktBuilder(pkt=base_pkt/pad, vm=vm)
+        pkt = STLPktBuilder(pkt=base_pkt / pad, vm=vm)
 
         return STLStream(packet=pkt, mode=STLTXCont())
 
-    def get_streams (self, direction = 0, **kwargs):
+    def get_streams(self, direction=0, **kwargs):
         return [self.create_stream()]
 
 
 # dynamic load - used for trex console or simulator
 def register():
     return STLS1()
-
-
-
diff --git a/src/plugins/nat/extras/nat_out2in_100ks.py b/src/plugins/nat/extras/nat_out2in_100ks.py
index 55ab5d42ee1..911f2cefda4 100644
--- a/src/plugins/nat/extras/nat_out2in_100ks.py
+++ b/src/plugins/nat/extras/nat_out2in_100ks.py
@@ -1,35 +1,39 @@
 from trex_stl_lib.api import *
 
-class STLS1:
 
-    def create_stream (self):
-        base_pkt = Ether()/IP(src="2.2.0.1")/UDP(sport=12)
+class STLS1:
+    def create_stream(self):
+        base_pkt = Ether() / IP(src="2.2.0.1") / UDP(sport=12)
 
         pad = Padding()
         if len(base_pkt) < 64:
             pad_len = 64 - len(base_pkt)
-            pad.load = '\x00' * pad_len
+            pad.load = "\x00" * pad_len
 
         vm = STLVM()
 
-        vm.tuple_var(name="tuple", ip_min="173.16.1.3", ip_max="173.16.4.234", port_min=1025, port_max=1124, limit_flows = 100000)
+        vm.tuple_var(
+            name="tuple",
+            ip_min="173.16.1.3",
+            ip_max="173.16.4.234",
+            port_min=1025,
+            port_max=1124,
+            limit_flows=100000,
+        )
 
         vm.write(fv_name="tuple.ip", pkt_offset="IP.dst")
         vm.fix_chksum()
 
         vm.write(fv_name="tuple.port", pkt_offset="UDP.dport")
 
-        pkt = STLPktBuilder(pkt=base_pkt/pad, vm=vm)
+        pkt = STLPktBuilder(pkt=base_pkt / pad, vm=vm)
 
         return STLStream(packet=pkt, mode=STLTXCont())
 
-    def get_streams (self, direction = 0, **kwargs):
+    def get_streams(self, direction=0, **kwargs):
         return [self.create_stream()]
 
 
 # dynamic load - used for trex console or simulator
 def register():
     return STLS1()
-
-
-
diff --git a/src/plugins/nat/extras/nat_out2in_10Ms.py b/src/plugins/nat/extras/nat_out2in_10Ms.py
index 48d3d199080..b3493641ea0 100644
--- a/src/plugins/nat/extras/nat_out2in_10Ms.py
+++ b/src/plugins/nat/extras/nat_out2in_10Ms.py
@@ -1,35 +1,39 @@
 from trex_stl_lib.api import *
 
-class STLS1:
 
-    def create_stream (self):
-        base_pkt = Ether()/IP(src="2.2.0.1")/UDP(sport=12)
+class STLS1:
+    def create_stream(self):
+        base_pkt = Ether() / IP(src="2.2.0.1") / UDP(sport=12)
 
         pad = Padding()
         if len(base_pkt) < 64:
             pad_len = 64 - len(base_pkt)
-            pad.load = '\x00' * pad_len
+            pad.load = "\x00" * pad_len
 
         vm = STLVM()
 
-        vm.tuple_var(name="tuple", ip_min="173.16.1.3", ip_max="173.17.135.162", port_min=1025, port_max=1124, limit_flows = 10000000)
+        vm.tuple_var(
+            name="tuple",
+            ip_min="173.16.1.3",
+            ip_max="173.17.135.162",
+            port_min=1025,
+            port_max=1124,
+            limit_flows=10000000,
+        )
 
         vm.write(fv_name="tuple.ip", pkt_offset="IP.dst")
         vm.fix_chksum()
 
         vm.write(fv_name="tuple.port", pkt_offset="UDP.dport")
 
-        pkt = STLPktBuilder(pkt=base_pkt/pad, vm=vm)
+        pkt = STLPktBuilder(pkt=base_pkt / pad, vm=vm)
 
         return STLStream(packet=pkt, mode=STLTXCont())
 
-    def get_streams (self, direction = 0, **kwargs):
+    def get_streams(self, direction=0, **kwargs):
         return [self.create_stream()]
 
 
 # dynamic load - used for trex console or simulator
 def register():
     return STLS1()
-
-
-
diff --git a/src/plugins/nat/extras/nat_out2in_10ks.py b/src/plugins/nat/extras/nat_out2in_10ks.py
index e961504fcf9..abd82ce320d 100644
--- a/src/plugins/nat/extras/nat_out2in_10ks.py
+++ b/src/plugins/nat/extras/nat_out2in_10ks.py
@@ -1,35 +1,39 @@
 from trex_stl_lib.api import *
 
-class STLS1:
 
-    def create_stream (self):
-        base_pkt = Ether()/IP(src="2.2.0.1")/UDP(sport=12)
+class STLS1:
+    def create_stream(self):
+        base_pkt = Ether() / IP(src="2.2.0.1") / UDP(sport=12)
 
         pad = Padding()
         if len(base_pkt) < 64:
             pad_len = 64 - len(base_pkt)
-            pad.load = '\x00' * pad_len
+            pad.load = "\x00" * pad_len
 
         vm = STLVM()
 
-        vm.tuple_var(name="tuple", ip_min="173.16.1.3", ip_max="173.16.1.102", port_min=1025, port_max=1124, limit_flows = 100000)
+        vm.tuple_var(
+            name="tuple",
+            ip_min="173.16.1.3",
+            ip_max="173.16.1.102",
+            port_min=1025,
+            port_max=1124,
+            limit_flows=100000,
+        )
 
         vm.write(fv_name="tuple.ip", pkt_offset="IP.dst")
         vm.fix_chksum()
 
         vm.write(fv_name="tuple.port", pkt_offset="UDP.dport")
 
-        pkt = STLPktBuilder(pkt=base_pkt/pad, vm=vm)
+        pkt = STLPktBuilder(pkt=base_pkt / pad, vm=vm)
 
         return STLStream(packet=pkt, mode=STLTXCont())
 
-    def get_streams (self, direction = 0, **kwargs):
+    def get_streams(self, direction=0, **kwargs):
         return [self.create_stream()]
 
 
 # dynamic load - used for trex console or simulator
 def register():
     return STLS1()
-
-
-
diff --git a/src/plugins/nat/extras/nat_out2in_1Ms.py b/src/plugins/nat/extras/nat_out2in_1Ms.py
index d2cb0810263..c08ef191e6c 100644
--- a/src/plugins/nat/extras/nat_out2in_1Ms.py
+++ b/src/plugins/nat/extras/nat_out2in_1Ms.py
@@ -1,35 +1,39 @@
 from trex_stl_lib.api import *
 
-class STLS1:
 
-    def create_stream (self):
-        base_pkt = Ether()/IP(src="2.2.0.1")/UDP(sport=12)
+class STLS1:
+    def create_stream(self):
+        base_pkt = Ether() / IP(src="2.2.0.1") / UDP(sport=12)
 
         pad = Padding()
         if len(base_pkt) < 64:
             pad_len = 64 - len(base_pkt)
-            pad.load = '\x00' * pad_len
+            pad.load = "\x00" * pad_len
 
         vm = STLVM()
 
-        vm.tuple_var(name="tuple", ip_min="173.16.1.3", ip_max="173.16.40.18", port_min=1025, port_max=1124, limit_flows = 1000000)
+        vm.tuple_var(
+            name="tuple",
+            ip_min="173.16.1.3",
+            ip_max="173.16.40.18",
+            port_min=1025,
+            port_max=1124,
+            limit_flows=1000000,
+        )
 
         vm.write(fv_name="tuple.ip", pkt_offset="IP.dst")
         vm.fix_chksum()
 
         vm.write(fv_name="tuple.port", pkt_offset="UDP.dport")
 
-        pkt = STLPktBuilder(pkt=base_pkt/pad, vm=vm)
+        pkt = STLPktBuilder(pkt=base_pkt / pad, vm=vm)
 
         return STLStream(packet=pkt, mode=STLTXCont())
 
-    def get_streams (self, direction = 0, **kwargs):
+    def get_streams(self, direction=0, **kwargs):
         return [self.create_stream()]
 
 
 # dynamic load - used for trex console or simulator
 def register():
     return STLS1()
-
-
-
diff --git a/src/plugins/nat/extras/nat_ses_open.py b/src/plugins/nat/extras/nat_ses_open.py
index d614d4e7356..a267a6b67fb 100644
--- a/src/plugins/nat/extras/nat_ses_open.py
+++ b/src/plugins/nat/extras/nat_ses_open.py
@@ -1,44 +1,72 @@
 from trex_stl_lib.api import *
 
-class STLS1:
 
-    def __init__ (self):
-        self.ip_range = {'local': {'start': "10.0.0.3", 'end': "10.1.255.255"},
-                         'external': {'start': "172.16.1.3", 'end': "172.16.1.3"},
-                         'remote': {'start': "2.2.0.1", 'end': "2.2.0.1"}}
-        self.port_range = {'local': {'start': 1025, 'end': 65535},
-                           'remote': {'start': 12, 'end': 12}}
+class STLS1:
+    def __init__(self):
+        self.ip_range = {
+            "local": {"start": "10.0.0.3", "end": "10.1.255.255"},
+            "external": {"start": "172.16.1.3", "end": "172.16.1.3"},
+            "remote": {"start": "2.2.0.1", "end": "2.2.0.1"},
+        }
+        self.port_range = {
+            "local": {"start": 1025, "end": 65535},
+            "remote": {"start": 12, "end": 12},
+        }
 
-    def create_stream (self, vm):
-        base_pkt = Ether()/IP()/UDP()
+    def create_stream(self, vm):
+        base_pkt = Ether() / IP() / UDP()
 
         if len(base_pkt) < 64:
             pad_len = 64 - len(base_pkt)
             pad = Padding()
-            pad.load = '\x00' * pad_len
-            base_pkt = base_pkt/pad
-            
+            pad.load = "\x00" * pad_len
+            base_pkt = base_pkt / pad
+
         pkt = STLPktBuilder(pkt=base_pkt, vm=vm)
         return STLStream(packet=pkt, mode=STLTXCont())
 
-    def get_streams (self, direction = 0, **kwargs):
+    def get_streams(self, direction=0, **kwargs):
         if direction == 0:
-            ip_src = self.ip_range['remote']
-            ip_dst = self.ip_range['external']
-            src_port = self.port_range['remote']
-            dst_port = self.port_range['local']
+            ip_src = self.ip_range["remote"]
+            ip_dst = self.ip_range["external"]
+            src_port = self.port_range["remote"]
+            dst_port = self.port_range["local"]
         else:
-            ip_src = self.ip_range['local']
-            ip_dst = self.ip_range['remote']
-            src_port = self.port_range['local']
-            dst_port = self.port_range['remote']
+            ip_src = self.ip_range["local"]
+            ip_dst = self.ip_range["remote"]
+            src_port = self.port_range["local"]
+            dst_port = self.port_range["remote"]
 
         vm = STLVM()
 
-        vm.var(name="ip_src", min_value=ip_src['start'], max_value=ip_src['end'], size=4, op="random")
-        vm.var(name="ip_dst", min_value=ip_dst['start'], max_value=ip_dst['end'], size=4, op="random")
-        vm.var(name="src_port", min_value=src_port['start'], max_value=src_port['end'], size=2, op="random")
-        vm.var(name="dst_port", min_value=dst_port['start'], max_value=dst_port['end'], size=2, op="random")
+        vm.var(
+            name="ip_src",
+            min_value=ip_src["start"],
+            max_value=ip_src["end"],
+            size=4,
+            op="random",
+        )
+        vm.var(
+            name="ip_dst",
+            min_value=ip_dst["start"],
+            max_value=ip_dst["end"],
+            size=4,
+            op="random",
+        )
+        vm.var(
+            name="src_port",
+            min_value=src_port["start"],
+            max_value=src_port["end"],
+            size=2,
+            op="random",
+        )
+        vm.var(
+            name="dst_port",
+            min_value=dst_port["start"],
+            max_value=dst_port["end"],
+            size=2,
+            op="random",
+        )
 
         vm.write(fv_name="ip_src", pkt_offset="IP.src")
         vm.write(fv_name="ip_dst", pkt_offset="IP.dst")
@@ -47,12 +75,9 @@ class STLS1:
 
         vm.fix_chksum()
 
-        return [ self.create_stream(vm) ]
+        return [self.create_stream(vm)]
 
 
 # dynamic load - used for trex console or simulator
 def register():
     return STLS1()
-
-
-
diff --git a/src/plugins/nat/extras/nat_static_gen_cfg.py b/src/plugins/nat/extras/nat_static_gen_cfg.py
index 9e59bbfc0c2..009cf099582 100755
--- a/src/plugins/nat/extras/nat_static_gen_cfg.py
+++ b/src/plugins/nat/extras/nat_static_gen_cfg.py
@@ -2,24 +2,24 @@
 import ipaddress
 import argparse
 
-parser = argparse.ArgumentParser(description='Generate NAT plugin config.')
-parser.add_argument('static_map_num', metavar='N', type=int, nargs=1,
-                    help='number of static mappings')
+parser = argparse.ArgumentParser(description="Generate NAT plugin config.")
+parser.add_argument(
+    "static_map_num", metavar="N", type=int, nargs=1, help="number of static mappings"
+)
 args = parser.parse_args()
 
-file_name = 'nat_static_%s' % (args.static_map_num[0])
-outfile = open(file_name, 'w')
+file_name = "nat_static_%s" % (args.static_map_num[0])
+outfile = open(file_name, "w")
 
-outfile.write('set int ip address TenGigabitEthernet4/0/0 172.16.2.1/24\n')
-outfile.write('set int ip address TenGigabitEthernet4/0/1 173.16.1.1/24\n')
-outfile.write('set int state TenGigabitEthernet4/0/0 up\n')
-outfile.write('set int state TenGigabitEthernet4/0/1 up\n')
-outfile.write('ip route add 2.2.0.0/16 via 173.16.1.2 TenGigabitEthernet4/0/1\n')
-outfile.write('ip route add 10.0.0.0/24 via 172.16.2.2 TenGigabitEthernet4/0/0\n')
-outfile.write('set int nat44 in TenGigabitEthernet4/0/0 out TenGigabitEthernet4/0/1\n')
-
-for i in range (0, args.static_map_num[0]):
-    local = str(ipaddress.IPv4Address(u'10.0.0.3') + i)
-    external = str(ipaddress.IPv4Address(u'173.16.1.3') + i)
-    outfile.write('nat44 add static mapping local %s external %s\n' % (local, external))
+outfile.write("set int ip address TenGigabitEthernet4/0/0 172.16.2.1/24\n")
+outfile.write("set int ip address TenGigabitEthernet4/0/1 173.16.1.1/24\n")
+outfile.write("set int state TenGigabitEthernet4/0/0 up\n")
+outfile.write("set int state TenGigabitEthernet4/0/1 up\n")
+outfile.write("ip route add 2.2.0.0/16 via 173.16.1.2 TenGigabitEthernet4/0/1\n")
+outfile.write("ip route add 10.0.0.0/24 via 172.16.2.2 TenGigabitEthernet4/0/0\n")
+outfile.write("set int nat44 in TenGigabitEthernet4/0/0 out TenGigabitEthernet4/0/1\n")
 
+for i in range(0, args.static_map_num[0]):
+    local = str(ipaddress.IPv4Address("10.0.0.3") + i)
+    external = str(ipaddress.IPv4Address("173.16.1.3") + i)
+    outfile.write("nat44 add static mapping local %s external %s\n" % (local, external))
diff --git a/src/plugins/nat/extras/nat_test_fast_path.py b/src/plugins/nat/extras/nat_test_fast_path.py
index e869d40872a..fb880fb9e96 100644
--- a/src/plugins/nat/extras/nat_test_fast_path.py
+++ b/src/plugins/nat/extras/nat_test_fast_path.py
@@ -2,7 +2,6 @@ from trex_stl_lib.api import *
 
 
 class STLS1:
-
     def create_stream(self):
         # base_pkt = Ether()/IP(dst="2.2.0.1")/UDP(dport=12)
 
@@ -24,37 +23,46 @@ class STLS1:
 
         # return STLStream(packet=pkt, mode=STLTXCont())
 
-        vm = STLScVmRaw([STLVmTupleGen(ip_min="10.0.0.1", ip_max="10.255.255.254",
-                                       port_min=1025, port_max=65535,
-                                       # name="stuple", limit_flows=10000),
-                                       name="stuple", limit_flows=100),
-                         STLVmTupleGen(ip_min="2.0.0.1", ip_max="2.255.255.254",
-                                       port_min=1025, port_max=65535,
-                                       # name="dtuple", limit_flows=100000000),
-                                       name="dtuple", limit_flows=100),
-
-                         # write ip to packet IP.src
-                         STLVmWrFlowVar(fv_name="stuple.ip",
-                                        pkt_offset="IP.src"),
-                         STLVmWrFlowVar(fv_name="dtuple.ip",
-                                        pkt_offset="IP.dst"),
-                         # fix checksum
-                         STLVmFixIpv4(offset="IP"),
-                         # write udp.port
-                         STLVmWrFlowVar(fv_name="stuple.port",
-                                        pkt_offset="UDP.sport"),
-                         STLVmWrFlowVar(fv_name="dtuple.port",
-                                        pkt_offset="UDP.dport"),
-                         ]
-                        )
-
-        base_pkt = Ether()/IP(src="16.0.0.1", dst="2.0.0.1")/UDP(dport=12, sport=1025)
+        vm = STLScVmRaw(
+            [
+                STLVmTupleGen(
+                    ip_min="10.0.0.1",
+                    ip_max="10.255.255.254",
+                    port_min=1025,
+                    port_max=65535,
+                    # name="stuple", limit_flows=10000),
+                    name="stuple",
+                    limit_flows=100,
+                ),
+                STLVmTupleGen(
+                    ip_min="2.0.0.1",
+                    ip_max="2.255.255.254",
+                    port_min=1025,
+                    port_max=65535,
+                    # name="dtuple", limit_flows=100000000),
+                    name="dtuple",
+                    limit_flows=100,
+                ),
+                # write ip to packet IP.src
+                STLVmWrFlowVar(fv_name="stuple.ip", pkt_offset="IP.src"),
+                STLVmWrFlowVar(fv_name="dtuple.ip", pkt_offset="IP.dst"),
+                # fix checksum
+                STLVmFixIpv4(offset="IP"),
+                # write udp.port
+                STLVmWrFlowVar(fv_name="stuple.port", pkt_offset="UDP.sport"),
+                STLVmWrFlowVar(fv_name="dtuple.port", pkt_offset="UDP.dport"),
+            ]
+        )
+
+        base_pkt = (
+            Ether() / IP(src="16.0.0.1", dst="2.0.0.1") / UDP(dport=12, sport=1025)
+        )
         pad = Padding()
         if len(base_pkt) < 64:
             pad_len = 64 - len(base_pkt)
-            pad.load = '\x00' * pad_len
+            pad.load = "\x00" * pad_len
 
-        pkt = STLPktBuilder(pkt=base_pkt/pad, vm=vm)
+        pkt = STLPktBuilder(pkt=base_pkt / pad, vm=vm)
 
         return STLStream(packet=pkt, mode=STLTXCont())
 
diff --git a/src/plugins/nat/extras/nat_test_slow_path.py b/src/plugins/nat/extras/nat_test_slow_path.py
index a6351b98adf..3145a2c6a59 100644
--- a/src/plugins/nat/extras/nat_test_slow_path.py
+++ b/src/plugins/nat/extras/nat_test_slow_path.py
@@ -2,7 +2,6 @@ from trex_stl_lib.api import *
 
 
 class STLS1:
-
     def create_stream(self):
         # base_pkt = Ether()/IP(dst="2.2.0.1")/UDP(dport=12)
 
@@ -24,35 +23,44 @@ class STLS1:
 
         # return STLStream(packet=pkt, mode=STLTXCont())
 
-        vm = STLScVmRaw([STLVmTupleGen(ip_min="10.0.0.1", ip_max="10.255.255.254",
-                                       port_min=1025, port_max=65535,
-                                       name="stuple", limit_flows=10000),
-                         STLVmTupleGen(ip_min="2.0.0.1", ip_max="2.255.255.254",
-                                       port_min=1025, port_max=65535,
-                                       name="dtuple", limit_flows=100000000),
-
-                         # write ip to packet IP.src
-                         STLVmWrFlowVar(fv_name="stuple.ip",
-                                        pkt_offset="IP.src"),
-                         STLVmWrFlowVar(fv_name="dtuple.ip",
-                                        pkt_offset="IP.dst"),
-                         # fix checksum
-                         STLVmFixIpv4(offset="IP"),
-                         # write udp.port
-                         STLVmWrFlowVar(fv_name="stuple.port",
-                                        pkt_offset="UDP.sport"),
-                         STLVmWrFlowVar(fv_name="dtuple.port",
-                                        pkt_offset="UDP.dport"),
-                         ]
-                        )
-
-        base_pkt = Ether()/IP(src="16.0.0.1", dst="2.0.0.1")/UDP(dport=12, sport=1025)
+        vm = STLScVmRaw(
+            [
+                STLVmTupleGen(
+                    ip_min="10.0.0.1",
+                    ip_max="10.255.255.254",
+                    port_min=1025,
+                    port_max=65535,
+                    name="stuple",
+                    limit_flows=10000,
+                ),
+                STLVmTupleGen(
+                    ip_min="2.0.0.1",
+                    ip_max="2.255.255.254",
+                    port_min=1025,
+                    port_max=65535,
+                    name="dtuple",
+                    limit_flows=100000000,
+                ),
+                # write ip to packet IP.src
+                STLVmWrFlowVar(fv_name="stuple.ip", pkt_offset="IP.src"),
+                STLVmWrFlowVar(fv_name="dtuple.ip", pkt_offset="IP.dst"),
+                # fix checksum
+                STLVmFixIpv4(offset="IP"),
+                # write udp.port
+                STLVmWrFlowVar(fv_name="stuple.port", pkt_offset="UDP.sport"),
+                STLVmWrFlowVar(fv_name="dtuple.port", pkt_offset="UDP.dport"),
+            ]
+        )
+
+        base_pkt = (
+            Ether() / IP(src="16.0.0.1", dst="2.0.0.1") / UDP(dport=12, sport=1025)
+        )
         pad = Padding()
         if len(base_pkt) < 64:
             pad_len = 64 - len(base_pkt)
-            pad.load = '\x00' * pad_len
+            pad.load = "\x00" * pad_len
 
-        pkt = STLPktBuilder(pkt=base_pkt/pad, vm=vm)
+        pkt = STLPktBuilder(pkt=base_pkt / pad, vm=vm)
 
         return STLStream(packet=pkt, mode=STLTXCont())
 
diff --git a/src/plugins/nat/extras/nat_test_slow_path_with_latency.py b/src/plugins/nat/extras/nat_test_slow_path_with_latency.py
index 6c7663434c5..0c08e7a5e80 100644
--- a/src/plugins/nat/extras/nat_test_slow_path_with_latency.py
+++ b/src/plugins/nat/extras/nat_test_slow_path_with_latency.py
@@ -2,7 +2,6 @@ from trex_stl_lib.api import *
 
 
 class STLS1:
-
     def create_stream(self, port_id):
         # base_pkt = Ether()/IP(dst="2.2.0.1")/UDP(dport=12)
 
@@ -24,49 +23,61 @@ class STLS1:
 
         # return STLStream(packet=pkt, mode=STLTXCont())
 
-        vm = STLScVmRaw([STLVmTupleGen(ip_min="10.0.0.1", ip_max="10.255.255.254",
-                                       port_min=1025, port_max=65535,
-                                       name="stuple", limit_flows=10000),
-                         STLVmTupleGen(ip_min="2.0.0.1", ip_max="2.255.255.254",
-                                       port_min=1025, port_max=65535,
-                                       name="dtuple", limit_flows=100000000),
-
-                         # write ip to packet IP.src
-                         STLVmWrFlowVar(fv_name="stuple.ip",
-                                        pkt_offset="IP.src"),
-                         STLVmWrFlowVar(fv_name="dtuple.ip",
-                                        pkt_offset="IP.dst"),
-                         # fix checksum
-                         STLVmFixIpv4(offset="IP"),
-                         # write udp.port
-                         STLVmWrFlowVar(fv_name="stuple.port",
-                                        pkt_offset="UDP.sport"),
-                         STLVmWrFlowVar(fv_name="dtuple.port",
-                                        pkt_offset="UDP.dport"),
-                         ]
-                        )
-
-        base_pkt = Ether()/IP(src="16.0.0.1", dst="2.0.0.1")/UDP(dport=12, sport=1025)
+        vm = STLScVmRaw(
+            [
+                STLVmTupleGen(
+                    ip_min="10.0.0.1",
+                    ip_max="10.255.255.254",
+                    port_min=1025,
+                    port_max=65535,
+                    name="stuple",
+                    limit_flows=10000,
+                ),
+                STLVmTupleGen(
+                    ip_min="2.0.0.1",
+                    ip_max="2.255.255.254",
+                    port_min=1025,
+                    port_max=65535,
+                    name="dtuple",
+                    limit_flows=100000000,
+                ),
+                # write ip to packet IP.src
+                STLVmWrFlowVar(fv_name="stuple.ip", pkt_offset="IP.src"),
+                STLVmWrFlowVar(fv_name="dtuple.ip", pkt_offset="IP.dst"),
+                # fix checksum
+                STLVmFixIpv4(offset="IP"),
+                # write udp.port
+                STLVmWrFlowVar(fv_name="stuple.port", pkt_offset="UDP.sport"),
+                STLVmWrFlowVar(fv_name="dtuple.port", pkt_offset="UDP.dport"),
+            ]
+        )
+
+        base_pkt = (
+            Ether() / IP(src="16.0.0.1", dst="2.0.0.1") / UDP(dport=12, sport=1025)
+        )
         pad = Padding()
         if len(base_pkt) < 64:
             pad_len = 64 - len(base_pkt)
-            pad.load = '\x00' * pad_len
+            pad.load = "\x00" * pad_len
 
-        pad = max(0, 64 - len(base_pkt)) * 'x'
-        pad_latency = max(0, (64-4) - len(base_pkt)) * 'x'
+        pad = max(0, 64 - len(base_pkt)) * "x"
+        pad_latency = max(0, (64 - 4) - len(base_pkt)) * "x"
 
-        pkt = STLPktBuilder(pkt=base_pkt/pad, vm=vm)
+        pkt = STLPktBuilder(pkt=base_pkt / pad, vm=vm)
 
-        return [STLStream(packet=pkt, mode=STLTXCont()),
-                  # latency stream   
-                  STLStream(packet = STLPktBuilder(pkt = base_pkt/pad_latency),
-                            mode = STLTXCont(pps=1000),
-                            flow_stats = STLFlowLatencyStats(pg_id = 12+port_id))
-                  ]
+        return [
+            STLStream(packet=pkt, mode=STLTXCont()),
+            # latency stream
+            STLStream(
+                packet=STLPktBuilder(pkt=base_pkt / pad_latency),
+                mode=STLTXCont(pps=1000),
+                flow_stats=STLFlowLatencyStats(pg_id=12 + port_id),
+            ),
+        ]
 
     def get_streams(self, direction=0, **kwargs):
         # return [self.create_stream()]
-        return self.create_stream(kwargs['port_id'])
+        return self.create_stream(kwargs["port_id"])
 
 
 # dynamic load - used for trex console or simulator