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>
diff --git a/extras/vpp_config/scripts/dpdk-devbind.py b/extras/vpp_config/scripts/dpdk-devbind.py
index 80edb3b..140e434 100755
--- a/extras/vpp_config/scripts/dpdk-devbind.py
+++ b/extras/vpp_config/scripts/dpdk-devbind.py
@@ -56,9 +56,10 @@
 
 
 def usage():
-    '''Print usage information for the program'''
+    """Print usage information for the program"""
     argv0 = basename(sys.argv[0])
-    print("""
+    print(
+        """
 Usage:
 ------
 
@@ -115,33 +116,40 @@
 To bind 0000:02:00.0 and 0000:02:00.1 to the ixgbe kernel driver
         %(argv0)s -b ixgbe 02:00.0 02:00.1
 
-    """ % locals())  # replace items from local variables
+    """
+        % locals()
+    )  # replace items from local variables
 
 
 # This is roughly compatible with check_output function in subprocess module
 # which is only available in python 2.7.
 def check_output(args, stderr=None):
-    '''Run a command and capture its output'''
-    return subprocess.Popen(args, stdout=subprocess.PIPE,
-                            stderr=stderr).communicate()[0]
+    """Run a command and capture its output"""
+    return subprocess.Popen(args, stdout=subprocess.PIPE, stderr=stderr).communicate()[
+        0
+    ]
 
 
 def find_module(mod):
-    '''find the .ko file for kernel module named mod.
+    """find the .ko file for kernel module named mod.
     Searches the $RTE_SDK/$RTE_TARGET directory, the kernel
     modules directory and finally under the parent directory of
-    the script '''
+    the script"""
     # check $RTE_SDK/$RTE_TARGET directory
-    if 'RTE_SDK' in os.environ and 'RTE_TARGET' in os.environ:
-        path = "%s/%s/kmod/%s.ko" % (os.environ['RTE_SDK'],
-                                     os.environ['RTE_TARGET'], mod)
+    if "RTE_SDK" in os.environ and "RTE_TARGET" in os.environ:
+        path = "%s/%s/kmod/%s.ko" % (
+            os.environ["RTE_SDK"],
+            os.environ["RTE_TARGET"],
+            mod,
+        )
         if exists(path):
             return path
 
     # check using depmod
     try:
-        depmod_out = check_output(["modinfo", "-n", mod],
-                                  stderr=subprocess.STDOUT).lower()
+        depmod_out = check_output(
+            ["modinfo", "-n", mod], stderr=subprocess.STDOUT
+        ).lower()
         if "error" not in depmod_out:
             path = depmod_out.strip()
             if exists(path):
@@ -151,7 +159,7 @@
 
     # check for a copy based off current path
     tools_dir = dirname(abspath(sys.argv[0]))
-    if (tools_dir.endswith("tools")):
+    if tools_dir.endswith("tools"):
         base_dir = dirname(tools_dir)
         find_out = check_output(["find", base_dir, "-name", mod + ".ko"])
         if len(find_out) > 0:  # something matched
@@ -161,7 +169,7 @@
 
 
 def check_modules():
-    '''Checks that igb_uio is loaded'''
+    """Checks that igb_uio is loaded"""
     global dpdk_drivers
 
     # list of supported modules
@@ -170,20 +178,21 @@
     # first check if module is loaded
     try:
         # Get list of sysfs modules (both built-in and dynamically loaded)
-        sysfs_path = '/sys/module/'
+        sysfs_path = "/sys/module/"
 
         # Get the list of directories in sysfs_path
-        sysfs_mods = [os.path.join(sysfs_path, o) for o
-                      in os.listdir(sysfs_path)
-                      if os.path.isdir(os.path.join(sysfs_path, o))]
+        sysfs_mods = [
+            os.path.join(sysfs_path, o)
+            for o in os.listdir(sysfs_path)
+            if os.path.isdir(os.path.join(sysfs_path, o))
+        ]
 
         # Extract the last element of '/sys/module/abc' in the array
-        sysfs_mods = [a.split('/')[-1] for a in sysfs_mods]
+        sysfs_mods = [a.split("/")[-1] for a in sysfs_mods]
 
         # special case for vfio_pci (module is named vfio-pci,
         # but its .ko is named vfio_pci)
-        sysfs_mods = map(lambda a:
-                         a if a != 'vfio_pci' else 'vfio-pci', sysfs_mods)
+        sysfs_mods = map(lambda a: a if a != "vfio_pci" else "vfio-pci", sysfs_mods)
 
         for mod in mods:
             if mod["Name"] in sysfs_mods:
@@ -204,12 +213,12 @@
 
 
 def has_driver(dev_id):
-    '''return true if a device is assigned to a driver. False otherwise'''
+    """return true if a device is assigned to a driver. False otherwise"""
     return "Driver_str" in devices[dev_id]
 
 
 def get_pci_device_details(dev_id):
-    '''This function gets additional details for a PCI device'''
+    """This function gets additional details for a PCI device"""
     device = {}
 
     extra_info = check_output(["lspci", "-vmmks", dev_id]).splitlines()
@@ -225,8 +234,7 @@
     device["Interface"] = ""
     for base, dirs, _ in os.walk("/sys/bus/pci/devices/%s/" % dev_id):
         if "net" in dirs:
-            device["Interface"] = \
-                ",".join(os.listdir(os.path.join(base, "net")))
+            device["Interface"] = ",".join(os.listdir(os.path.join(base, "net")))
             break
     # check if a port is used for ssh connection
     device["Ssh_if"] = False
@@ -236,9 +244,9 @@
 
 
 def get_nic_details():
-    '''This function populates the "devices" dictionary. The keys used are
+    """This function populates the "devices" dictionary. The keys used are
     the pci addresses (domain:bus:slot.func). The values are themselves
-    dictionaries - one for each NIC.'''
+    dictionaries - one for each NIC."""
     global devices
     global dpdk_drivers
 
@@ -249,7 +257,7 @@
     dev = {}
     dev_lines = check_output(["lspci", "-Dvmmn"]).splitlines()
     for dev_line in dev_lines:
-        if (len(dev_line) == 0):
+        if len(dev_line) == 0:
             if dev["Class"][0:2] == NETWORK_BASE_CLASS:
                 # convert device and vendor ids to numbers, then add to global
                 dev["Vendor"] = int(dev["Vendor"], 16)
@@ -265,12 +273,13 @@
     ssh_if = []
     route = check_output(["ip", "-o", "route"])
     # filter out all lines for 169.254 routes
-    route = "\n".join(filter(lambda ln: not ln.startswith("169.254"),
-                             route.decode().splitlines()))
+    route = "\n".join(
+        filter(lambda ln: not ln.startswith("169.254"), route.decode().splitlines())
+    )
     rt_info = route.split()
     for i in range(len(rt_info) - 1):
         if rt_info[i] == "dev":
-            ssh_if.append(rt_info[i+1])
+            ssh_if.append(rt_info[i + 1])
 
     # based on the basic info, get extended text details
     for d in devices.keys():
@@ -288,8 +297,7 @@
         if "Module_str" in devices[d]:
             for driver in dpdk_drivers:
                 if driver not in devices[d]["Module_str"]:
-                    devices[d]["Module_str"] = \
-                        devices[d]["Module_str"] + ",%s" % driver
+                    devices[d]["Module_str"] = devices[d]["Module_str"] + ",%s" % driver
         else:
             devices[d]["Module_str"] = ",".join(dpdk_drivers)
 
@@ -302,9 +310,9 @@
 
 
 def get_crypto_details():
-    '''This function populates the "devices" dictionary. The keys used are
+    """This function populates the "devices" dictionary. The keys used are
     the pci addresses (domain:bus:slot.func). The values are themselves
-    dictionaries - one for each NIC.'''
+    dictionaries - one for each NIC."""
     global devices
     global dpdk_drivers
 
@@ -315,8 +323,8 @@
     dev = {}
     dev_lines = check_output(["lspci", "-Dvmmn"]).splitlines()
     for dev_line in dev_lines:
-        if (len(dev_line) == 0):
-            if (dev["Class"][0:2] == CRYPTO_BASE_CLASS):
+        if len(dev_line) == 0:
+            if dev["Class"][0:2] == CRYPTO_BASE_CLASS:
                 # convert device and vendor ids to numbers, then add to global
                 dev["Vendor"] = int(dev["Vendor"], 16)
                 dev["Device"] = int(dev["Device"], 16)
@@ -336,8 +344,7 @@
         if "Module_str" in devices[d]:
             for driver in dpdk_drivers:
                 if driver not in devices[d]["Module_str"]:
-                    devices[d]["Module_str"] = \
-                        devices[d]["Module_str"] + ",%s" % driver
+                    devices[d]["Module_str"] = devices[d]["Module_str"] + ",%s" % driver
         else:
             devices[d]["Module_str"] = ",".join(dpdk_drivers)
 
@@ -350,9 +357,9 @@
 
 
 def dev_id_from_dev_name(dev_name):
-    '''Take a device "name" - a string passed in by user to identify a NIC
+    """Take a device "name" - a string passed in by user to identify a NIC
     device, and determine the device id - i.e. the domain:bus:slot.func - for
-    it, which can then be used to index into the devices array'''
+    it, which can then be used to index into the devices array"""
 
     # check if it's already a suitable index
     if dev_name in devices:
@@ -366,23 +373,29 @@
             if dev_name in devices[d]["Interface"].split(","):
                 return devices[d]["Slot"]
     # if nothing else matches - error
-    print("Unknown device: %s. "
-          "Please specify device in \"bus:slot.func\" format" % dev_name)
+    print(
+        "Unknown device: %s. "
+        'Please specify device in "bus:slot.func" format' % dev_name
+    )
     sys.exit(1)
 
 
 def unbind_one(dev_id, force):
-    '''Unbind the device identified by "dev_id" from its current driver'''
+    """Unbind the device identified by "dev_id" from its current driver"""
     dev = devices[dev_id]
     if not has_driver(dev_id):
-        print("%s %s %s is not currently managed by any driver\n" %
-              (dev["Slot"], dev["Device_str"], dev["Interface"]))
+        print(
+            "%s %s %s is not currently managed by any driver\n"
+            % (dev["Slot"], dev["Device_str"], dev["Interface"])
+        )
         return
 
     # prevent us disconnecting ourselves
     if dev["Ssh_if"] and not force:
-        print("Routing table indicates that interface %s is active. "
-              "Skipping unbind" % (dev_id))
+        print(
+            "Routing table indicates that interface %s is active. "
+            "Skipping unbind" % (dev_id)
+        )
         return
 
     # write to /sys to unbind
@@ -390,30 +403,30 @@
     try:
         f = open(filename, "a")
     except:
-        print("Error: unbind failed for %s - Cannot open %s"
-              % (dev_id, filename))
+        print("Error: unbind failed for %s - Cannot open %s" % (dev_id, filename))
         sys.exit(1)
     f.write(dev_id)
     f.close()
 
 
 def bind_one(dev_id, driver, force):
-    '''Bind the device given by "dev_id" to the driver "driver". If the device
-    is already bound to a different driver, it will be unbound first'''
+    """Bind the device given by "dev_id" to the driver "driver". If the device
+    is already bound to a different driver, it will be unbound first"""
     dev = devices[dev_id]
     saved_driver = None  # used to rollback any unbind in case of failure
 
     # prevent disconnection of our ssh session
     if dev["Ssh_if"] and not force:
-        print("Routing table indicates that interface %s is active. "
-              "Not modifying" % (dev_id))
+        print(
+            "Routing table indicates that interface %s is active. "
+            "Not modifying" % (dev_id)
+        )
         return
 
     # unbind any existing drivers we don't want
     if has_driver(dev_id):
         if dev["Driver_str"] == driver:
-            print("%s already bound to driver %s, skipping\n"
-                  % (dev_id, driver))
+            print("%s already bound to driver %s, skipping\n" % (dev_id, driver))
             return
         else:
             saved_driver = dev["Driver_str"]
@@ -426,15 +439,16 @@
         try:
             f = open(filename, "w")
         except:
-            print("Error: bind failed for %s - Cannot open %s"
-                  % (dev_id, filename))
+            print("Error: bind failed for %s - Cannot open %s" % (dev_id, filename))
             return
         try:
             f.write("%04x %04x" % (dev["Vendor"], dev["Device"]))
             f.close()
         except:
-            print("Error: bind failed for %s - Cannot write new PCI ID to "
-                  "driver %s" % (dev_id, driver))
+            print(
+                "Error: bind failed for %s - Cannot write new PCI ID to "
+                "driver %s" % (dev_id, driver)
+            )
             return
 
     # do the bind by writing to /sys
@@ -442,8 +456,7 @@
     try:
         f = open(filename, "a")
     except:
-        print("Error: bind failed for %s - Cannot open %s"
-              % (dev_id, filename))
+        print("Error: bind failed for %s - Cannot open %s" % (dev_id, filename))
         if saved_driver is not None:  # restore any previous driver
             bind_one(dev_id, saved_driver, force)
         return
@@ -457,8 +470,7 @@
         tmp = get_pci_device_details(dev_id)
         if "Driver_str" in tmp and tmp["Driver_str"] == driver:
             return
-        print("Error: bind failed for %s - Cannot bind to driver %s"
-              % (dev_id, driver))
+        print("Error: bind failed for %s - Cannot bind to driver %s" % (dev_id, driver))
         if saved_driver is not None:  # restore any previous driver
             bind_one(dev_id, saved_driver, force)
         return
@@ -491,8 +503,7 @@
             continue
 
         # update information about this device
-        devices[d] = dict(devices[d].items() +
-                          get_pci_device_details(d).items())
+        devices[d] = dict(devices[d].items() + get_pci_device_details(d).items())
 
         # check if updated information indicates that the device was bound
         if "Driver_str" in devices[d]:
@@ -500,20 +511,21 @@
 
 
 def display_devices(title, dev_list, extra_params=None):
-    '''Displays to the user the details of a list of devices given in
+    """Displays to the user the details of a list of devices given in
     "dev_list". The "extra_params" parameter, if given, should contain a string
      with %()s fields in it for replacement by the named fields in each
-     device's dictionary.'''
+     device's dictionary."""
     strings = []  # this holds the strings to print. We sort before printing
     print("\n%s" % title)
-    print("="*len(title))
+    print("=" * len(title))
     if len(dev_list) == 0:
         strings.append("<none>")
     else:
         for dev in dev_list:
             if extra_params is not None:
-                strings.append("%s '%s' %s" % (dev["Slot"],
-                               dev["Device_str"], extra_params % dev))
+                strings.append(
+                    "%s '%s' %s" % (dev["Slot"], dev["Device_str"], extra_params % dev)
+                )
             else:
                 strings.append("%s '%s'" % (dev["Slot"], dev["Device_str"]))
     # sort before printing, so that the entries appear in PCI order
@@ -522,9 +534,9 @@
 
 
 def show_status():
-    '''Function called when the script is passed the "--status" option.
+    """Function called when the script is passed the "--status" option.
     Displays to the user what devices are bound to the igb_uio driver, the
-    kernel driver or to no driver'''
+    kernel driver or to no driver"""
     global dpdk_drivers
     kernel_drv = []
     dpdk_drv = []
@@ -532,7 +544,7 @@
 
     # split our list of network devices into the three categories above
     for d in devices.keys():
-        if (NETWORK_BASE_CLASS in devices[d]["Class"]):
+        if NETWORK_BASE_CLASS in devices[d]["Class"]:
             if not has_driver(d):
                 no_drv.append(devices[d])
                 continue
@@ -542,11 +554,16 @@
                 kernel_drv.append(devices[d])
 
     # print each category separately, so we can clearly see what's used by DPDK
-    display_devices("Network devices using DPDK-compatible driver", dpdk_drv,
-                    "drv=%(Driver_str)s unused=%(Module_str)s")
-    display_devices("Network devices using kernel driver", kernel_drv,
-                    "if=%(Interface)s drv=%(Driver_str)s "
-                    "unused=%(Module_str)s %(Active)s")
+    display_devices(
+        "Network devices using DPDK-compatible driver",
+        dpdk_drv,
+        "drv=%(Driver_str)s unused=%(Module_str)s",
+    )
+    display_devices(
+        "Network devices using kernel driver",
+        kernel_drv,
+        "if=%(Interface)s drv=%(Driver_str)s " "unused=%(Module_str)s %(Active)s",
+    )
     display_devices("Other network devices", no_drv, "unused=%(Module_str)s")
 
     # split our list of crypto devices into the three categories above
@@ -555,7 +572,7 @@
     no_drv = []
 
     for d in devices.keys():
-        if (CRYPTO_BASE_CLASS in devices[d]["Class"]):
+        if CRYPTO_BASE_CLASS in devices[d]["Class"]:
             if not has_driver(d):
                 no_drv.append(devices[d])
                 continue
@@ -564,17 +581,22 @@
             else:
                 kernel_drv.append(devices[d])
 
-    display_devices("Crypto devices using DPDK-compatible driver", dpdk_drv,
-                    "drv=%(Driver_str)s unused=%(Module_str)s")
-    display_devices("Crypto devices using kernel driver", kernel_drv,
-                    "drv=%(Driver_str)s "
-                    "unused=%(Module_str)s")
+    display_devices(
+        "Crypto devices using DPDK-compatible driver",
+        dpdk_drv,
+        "drv=%(Driver_str)s unused=%(Module_str)s",
+    )
+    display_devices(
+        "Crypto devices using kernel driver",
+        kernel_drv,
+        "drv=%(Driver_str)s " "unused=%(Module_str)s",
+    )
     display_devices("Other crypto devices", no_drv, "unused=%(Module_str)s")
 
 
 def parse_args():
-    '''Parses the command-line arguments given by the user and takes the
-    appropriate action for each'''
+    """Parses the command-line arguments given by the user and takes the
+    appropriate action for each"""
     global b_flag
     global status_flag
     global force_flag
@@ -584,9 +606,11 @@
         sys.exit(0)
 
     try:
-        opts, args = getopt.getopt(sys.argv[1:], "b:us",
-                                   ["help", "usage", "status", "force",
-                                    "bind=", "unbind"])
+        opts, args = getopt.getopt(
+            sys.argv[1:],
+            "b:us",
+            ["help", "usage", "status", "force", "bind=", "unbind"],
+        )
     except getopt.GetoptError as error:
         print(str(error))
         print("Run '%s --usage' for further information" % sys.argv[0])
@@ -611,15 +635,14 @@
 
 
 def do_arg_actions():
-    '''do the actual action requested by the user'''
+    """do the actual action requested by the user"""
     global b_flag
     global status_flag
     global force_flag
     global args
 
     if b_flag is None and not status_flag:
-        print("Error: No action specified for devices."
-              "Please give a -b or -u option")
+        print("Error: No action specified for devices." "Please give a -b or -u option")
         print("Run '%s --usage' for further information" % sys.argv[0])
         sys.exit(1)
 
@@ -640,7 +663,7 @@
 
 
 def main():
-    '''program main function'''
+    """program main function"""
     parse_args()
     check_modules()
     get_nic_details()