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/src/vpp-api/python/vpp_papi/vpp_serializer.py b/src/vpp-api/python/vpp_papi/vpp_serializer.py
index 644aeac..a99e16a 100644
--- a/src/vpp-api/python/vpp_papi/vpp_serializer.py
+++ b/src/vpp-api/python/vpp_papi/vpp_serializer.py
@@ -27,7 +27,7 @@
 # logger = logging.getLogger('vpp_serializer')
 # logger.setLevel(logging.DEBUG)
 #
-logger = logging.getLogger('vpp_papi.serializer')
+logger = logging.getLogger("vpp_papi.serializer")
 
 
 def check(d):
@@ -46,8 +46,7 @@
 
 def conversion_packer(data, field_type):
     t = type(data).__name__
-    return types[field_type].pack(vpp_format.
-                                  conversion_table[field_type][t](data))
+    return types[field_type].pack(vpp_format.conversion_table[field_type][t](data))
 
 
 def conversion_unpacker(data, field_type):
@@ -77,30 +76,33 @@
                 return c._get_packer_with_options(f_type, options)
             except IndexError:
                 raise VPPSerializerValueError(
-                    "Options not supported for {}{} ({})".
-                    format(f_type, types[f_type].__class__,
-                           options))
+                    "Options not supported for {}{} ({})".format(
+                        f_type, types[f_type].__class__, options
+                    )
+                )
 
 
 class BaseTypes(Packer):
     def __init__(self, type, elements=0, options=None):
         self._type = type
         self._elements = elements
-        base_types = {'u8': '>B',
-                      'i8': '>b',
-                      'string': '>s',
-                      'u16': '>H',
-                      'i16': '>h',
-                      'u32': '>I',
-                      'i32': '>i',
-                      'u64': '>Q',
-                      'i64': '>q',
-                      'f64': '=d',
-                      'bool': '>?',
-                      'header': '>HI'}
+        base_types = {
+            "u8": ">B",
+            "i8": ">b",
+            "string": ">s",
+            "u16": ">H",
+            "i16": ">h",
+            "u32": ">I",
+            "i32": ">i",
+            "u64": ">Q",
+            "i64": ">q",
+            "f64": "=d",
+            "bool": ">?",
+            "header": ">HI",
+        }
 
-        if elements > 0 and (type == 'u8' or type == 'string'):
-            self.packer = struct.Struct('>%ss' % elements)
+        if elements > 0 and (type == "u8" or type == "string"):
+            self.packer = struct.Struct(">%ss" % elements)
         else:
             self.packer = struct.Struct(base_types[type])
         self.size = self.packer.size
@@ -108,8 +110,8 @@
 
     def pack(self, data, kwargs=None):
         if data is None:  # Default to zero if not specified
-            if self.options and 'default' in self.options:
-                data = self.options['default']
+            if self.options and "default" in self.options:
+                data = self.options["default"]
             else:
                 data = 0
         return self.packer.pack(data)
@@ -122,9 +124,11 @@
         return BaseTypes(f_type, options=options)
 
     def __repr__(self):
-        return "BaseTypes(type=%s, elements=%s, options=%s)" % (self._type,
-                                                                self._elements,
-                                                                self.options)
+        return "BaseTypes(type=%s, elements=%s, options=%s)" % (
+            self._type,
+            self._elements,
+            self.options,
+        )
 
 
 class String(Packer):
@@ -132,13 +136,15 @@
         self.name = name
         self.num = num
         self.size = 1
-        self.length_field_packer = BaseTypes('u32')
-        self.limit = options['limit'] if 'limit' in options else num
+        self.length_field_packer = BaseTypes("u32")
+        self.limit = options["limit"] if "limit" in options else num
         self.fixed = True if num else False
         if self.fixed and not self.limit:
             raise VPPSerializerValueError(
-                "Invalid combination for: {}, {} fixed:{} limit:{}".
-                format(name, options, self.fixed, self.limit))
+                "Invalid combination for: {}, {} fixed:{} limit:{}".format(
+                    name, options, self.fixed, self.limit
+                )
+            )
 
     def pack(self, list, kwargs=None):
         if not list:
@@ -147,34 +153,42 @@
             return self.length_field_packer.pack(0) + b""
         if self.limit and len(list) > self.limit - 1:
             raise VPPSerializerValueError(
-                "Invalid argument length for: {}, {} maximum {}".
-                format(list, len(list), self.limit - 1))
+                "Invalid argument length for: {}, {} maximum {}".format(
+                    list, len(list), self.limit - 1
+                )
+            )
         if self.fixed:
-            return list.encode('ascii').ljust(self.limit, b'\x00')
-        return self.length_field_packer.pack(len(list)) + list.encode('ascii')
+            return list.encode("ascii").ljust(self.limit, b"\x00")
+        return self.length_field_packer.pack(len(list)) + list.encode("ascii")
 
     def unpack(self, data, offset=0, result=None, ntc=False):
         if self.fixed:
-            p = BaseTypes('u8', self.num)
+            p = BaseTypes("u8", self.num)
             s = p.unpack(data, offset)
-            s2 = s[0].split(b'\0', 1)[0]
-            return (s2.decode('ascii'), self.num)
+            s2 = s[0].split(b"\0", 1)[0]
+            return (s2.decode("ascii"), self.num)
 
-        length, length_field_size = self.length_field_packer.unpack(data,
-                                                                    offset)
+        length, length_field_size = self.length_field_packer.unpack(data, offset)
         if length == 0:
-            return '', 0
-        p = BaseTypes('u8', length)
+            return "", 0
+        p = BaseTypes("u8", length)
         x, size = p.unpack(data, offset + length_field_size)
-        return (x.decode('ascii', errors='replace'), size + length_field_size)
+        return (x.decode("ascii", errors="replace"), size + length_field_size)
 
 
-types = {'u8': BaseTypes('u8'), 'i8': BaseTypes('i8'),
-         'u16': BaseTypes('u16'), 'i16': BaseTypes('i16'),
-         'u32': BaseTypes('u32'), 'i32': BaseTypes('i32'),
-         'u64': BaseTypes('u64'), 'i64': BaseTypes('i64'),
-         'f64': BaseTypes('f64'),
-         'bool': BaseTypes('bool'), 'string': String}
+types = {
+    "u8": BaseTypes("u8"),
+    "i8": BaseTypes("i8"),
+    "u16": BaseTypes("u16"),
+    "i16": BaseTypes("i16"),
+    "u32": BaseTypes("u32"),
+    "i32": BaseTypes("i32"),
+    "u64": BaseTypes("u64"),
+    "i64": BaseTypes("i64"),
+    "f64": BaseTypes("f64"),
+    "bool": BaseTypes("bool"),
+    "string": String,
+}
 
 class_types = {}
 
@@ -202,32 +216,34 @@
         """Packs a fixed length bytestring. Left-pads with zeros
         if input data is too short."""
         if not data:
-            return b'\x00' * self.size
+            return b"\x00" * self.size
 
         if len(data) > self.num:
             raise VPPSerializerValueError(
                 'Fixed list length error for "{}", got: {}'
-                ' expected: {}'
-                .format(self.name, len(data), self.num))
+                " expected: {}".format(self.name, len(data), self.num)
+            )
 
         try:
             return self.packer.pack(data)
         except struct.error:
             raise VPPSerializerValueError(
-                'Packing failed for "{}" {}'
-                .format(self.name, kwargs))
+                'Packing failed for "{}" {}'.format(self.name, kwargs)
+            )
 
     def unpack(self, data, offset=0, result=None, ntc=False):
         if len(data[offset:]) < self.num:
             raise VPPSerializerValueError(
                 'Invalid array length for "{}" got {}'
-                ' expected {}'
-                .format(self.name, len(data[offset:]), self.num))
+                " expected {}".format(self.name, len(data[offset:]), self.num)
+            )
         return self.packer.unpack(data, offset)
 
     def __repr__(self):
         return "FixedList_u8(name=%s, field_type=%s, num=%s)" % (
-            self.name, self.field_type, self.num
+            self.name,
+            self.field_type,
+            self.num,
         )
 
 
@@ -242,8 +258,10 @@
     def pack(self, list, kwargs):
         if len(list) != self.num:
             raise VPPSerializerValueError(
-                'Fixed list length error, got: {} expected: {}'
-                .format(len(list), self.num))
+                "Fixed list length error, got: {} expected: {}".format(
+                    len(list), self.num
+                )
+            )
         b = bytes()
         for e in list:
             b += self.packer.pack(e)
@@ -262,7 +280,10 @@
 
     def __repr__(self):
         return "FixedList(name=%s, field_type=%s, num=%s)" % (
-            self.name, self.field_type, self.num)
+            self.name,
+            self.field_type,
+            self.num,
+        )
 
 
 class VLAList(Packer):
@@ -279,13 +300,15 @@
             return b""
         if len(lst) != kwargs[self.length_field]:
             raise VPPSerializerValueError(
-                'Variable length error, got: {} expected: {}'
-                .format(len(lst), kwargs[self.length_field]))
+                "Variable length error, got: {} expected: {}".format(
+                    len(lst), kwargs[self.length_field]
+                )
+            )
 
         # u8 array
         if self.packer.size == 1:
             if isinstance(lst, list):
-                return b''.join(lst)
+                return b"".join(lst)
             return bytes(lst)
 
         b = bytes()
@@ -300,8 +323,8 @@
         # u8 array
         if self.packer.size == 1:
             if result[self.index] == 0:
-                return b'', 0
-            p = BaseTypes('u8', result[self.index])
+                return b"", 0
+            p = BaseTypes("u8", result[self.index])
             return p.unpack(data, offset, ntc=ntc)
 
         r = []
@@ -313,10 +336,12 @@
         return r, total
 
     def __repr__(self):
-        return "VLAList(name=%s, field_type=%s, " \
-               "len_field_name=%s, index=%s)" % (
-                   self.name, self.field_type, self.length_field, self.index
-               )
+        return "VLAList(name=%s, field_type=%s, " "len_field_name=%s, index=%s)" % (
+            self.name,
+            self.field_type,
+            self.length_field,
+            self.index,
+        )
 
 
 class VLAList_legacy(Packer):
@@ -340,7 +365,8 @@
         # Return a list of arguments
         if (len(data) - offset) % self.packer.size:
             raise VPPSerializerValueError(
-                'Legacy Variable Length Array length mismatch.')
+                "Legacy Variable Length Array length mismatch."
+            )
         elements = int((len(data) - offset) / self.packer.size)
         r = []
         for e in range(elements):
@@ -351,9 +377,7 @@
         return r, total
 
     def __repr__(self):
-        return "VLAList_legacy(name=%s, field_type=%s)" % (
-            self.name, self.field_type
-        )
+        return "VLAList_legacy(name=%s, field_type=%s)" % (self.name, self.field_type)
 
 
 # Will change to IntEnum after 21.04 release
@@ -361,16 +385,16 @@
     output_class = IntFlag
 
     def __init__(self, name, msgdef, options=None):
-        self.size = types['u32'].size
+        self.size = types["u32"].size
         self.name = name
-        self.enumtype = 'u32'
+        self.enumtype = "u32"
         self.msgdef = msgdef
         e_hash = {}
         for f in msgdef:
-            if type(f) is dict and 'enumtype' in f:
-                if f['enumtype'] != 'u32':
-                    self.size = types[f['enumtype']].size
-                    self.enumtype = f['enumtype']
+            if type(f) is dict and "enumtype" in f:
+                if f["enumtype"] != "u32":
+                    self.size = types[f["enumtype"]].size
+                    self.enumtype = f["enumtype"]
                 continue
             ename, evalue = f
             e_hash[ename] = evalue
@@ -387,8 +411,8 @@
 
     def pack(self, data, kwargs=None):
         if data is None:  # Default to zero if not specified
-            if self.options and 'default' in self.options:
-                data = self.options['default']
+            if self.options and "default" in self.options:
+                data = self.options["default"]
             else:
                 data = 0
 
@@ -404,7 +428,10 @@
 
     def __repr__(self):
         return "%s(name=%s, msgdef=%s, options=%s)" % (
-            self.__class__.__name__, self.name, self.msgdef, self.options
+            self.__class__.__name__,
+            self.name,
+            self.msgdef,
+            self.options,
         )
 
 
@@ -424,14 +451,13 @@
         fields = []
         self.packers = collections.OrderedDict()
         for i, f in enumerate(msgdef):
-            if type(f) is dict and 'crc' in f:
-                self.crc = f['crc']
+            if type(f) is dict and "crc" in f:
+                self.crc = f["crc"]
                 continue
             f_type, f_name = f
             if f_type not in types:
-                logger.debug('Unknown union type {}'.format(f_type))
-                raise VPPSerializerValueError(
-                    'Unknown message type {}'.format(f_type))
+                logger.debug("Unknown union type {}".format(f_type))
+                raise VPPSerializerValueError("Unknown message type {}".format(f_type))
             fields.append(f_name)
             size = types[f_type].size
             self.packers[f_name] = types[f_type]
@@ -445,14 +471,14 @@
     # Union of variable length?
     def pack(self, data, kwargs=None):
         if not data:
-            return b'\x00' * self.size
+            return b"\x00" * self.size
 
         for k, v in data.items():
             logger.debug("Key: {} Value: {}".format(k, v))
             b = self.packers[k].pack(v, kwargs)
             break
         r = bytearray(self.size)
-        r[:len(b)] = b
+        r[: len(b)] = b
         return r
 
     def unpack(self, data, offset=0, result=None, ntc=False):
@@ -466,25 +492,24 @@
         return self.tuple._make(r), maxsize
 
     def __repr__(self):
-        return"VPPUnionType(name=%s, msgdef=%r)" % (self.name, self.msgdef)
+        return "VPPUnionType(name=%s, msgdef=%r)" % (self.name, self.msgdef)
 
 
 class VPPTypeAlias(Packer):
     def __init__(self, name, msgdef, options=None):
         self.name = name
         self.msgdef = msgdef
-        t = vpp_get_type(msgdef['type'])
+        t = vpp_get_type(msgdef["type"])
         if not t:
-            raise ValueError('No such type: {}'.format(msgdef['type']))
-        if 'length' in msgdef:
-            if msgdef['length'] == 0:
+            raise ValueError("No such type: {}".format(msgdef["type"]))
+        if "length" in msgdef:
+            if msgdef["length"] == 0:
                 raise ValueError()
-            if msgdef['type'] == 'u8':
-                self.packer = FixedList_u8(name, msgdef['type'],
-                                           msgdef['length'])
+            if msgdef["type"] == "u8":
+                self.packer = FixedList_u8(name, msgdef["type"], msgdef["length"])
                 self.size = self.packer.size
             else:
-                self.packer = FixedList(name, msgdef['type'], msgdef['length'])
+                self.packer = FixedList(name, msgdef["type"], msgdef["length"])
         else:
             self.packer = t
             self.size = t.size
@@ -498,11 +523,11 @@
             try:
                 return conversion_packer(data, self.name)
             # Python 2 and 3 raises different exceptions from inet_pton
-            except(OSError, socket.error, TypeError):
+            except (OSError, socket.error, TypeError):
                 pass
         if data is None:  # Default to zero if not specified
-            if self.options and 'default' in self.options:
-                data = self.options['default']
+            if self.options and "default" in self.options:
+                data = self.options["default"]
             else:
                 data = 0
 
@@ -525,7 +550,10 @@
 
     def __repr__(self):
         return "VPPTypeAlias(name=%s, msgdef=%s, options=%s)" % (
-            self.name, self.msgdef, self.options)
+            self.name,
+            self.msgdef,
+            self.options,
+        )
 
 
 class VPPType(Packer):
@@ -539,17 +567,16 @@
         self.field_by_name = {}
         size = 0
         for i, f in enumerate(msgdef):
-            if type(f) is dict and 'crc' in f:
-                self.crc = f['crc']
+            if type(f) is dict and "crc" in f:
+                self.crc = f["crc"]
                 continue
             f_type, f_name = f[:2]
             self.fields.append(f_name)
             self.field_by_name[f_name] = None
             self.fieldtypes.append(f_type)
             if f_type not in types:
-                logger.debug('Unknown type {}'.format(f_type))
-                raise VPPSerializerValueError(
-                    'Unknown message type {}'.format(f_type))
+                logger.debug("Unknown type {}".format(f_type))
+                raise VPPSerializerValueError("Unknown message type {}".format(f_type))
 
             fieldlen = len(f)
             options = [x for x in f if type(x) is dict]
@@ -561,16 +588,16 @@
             if fieldlen == 3:  # list
                 list_elements = f[2]
                 if list_elements == 0:
-                    if f_type == 'string':
+                    if f_type == "string":
                         p = String(f_name, 0, self.options)
                     else:
                         p = VLAList_legacy(f_name, f_type)
                     self.packers.append(p)
-                elif f_type == 'u8':
+                elif f_type == "u8":
                     p = FixedList_u8(f_name, f_type, list_elements)
                     self.packers.append(p)
                     size += p.size
-                elif f_type == 'string':
+                elif f_type == "string":
                     p = String(f_name, list_elements, self.options)
                     self.packers.append(p)
                     size += p.size
@@ -584,7 +611,7 @@
                 self.packers.append(p)
             else:
                 # default support for types that decay to basetype
-                if 'default' in self.options:
+                if "default" in self.options:
                     p = self.get_packer_with_options(f_type, self.options)
                 else:
                     p = types[f_type]
@@ -609,8 +636,8 @@
         for i, a in enumerate(self.fields):
             if data and type(data) is not dict and a not in data:
                 raise VPPSerializerValueError(
-                    "Invalid argument: {} expected {}.{}".
-                    format(data, self.name, a))
+                    "Invalid argument: {} expected {}.{}".format(data, self.name, a)
+                )
 
             # Defaulting to zero.
             if not data or a not in data:  # Default to 0
@@ -651,7 +678,9 @@
 
     def __repr__(self):
         return "%s(name=%s, msgdef=%s)" % (
-            self.__class__.__name__, self.name, self.msgdef
+            self.__class__.__name__,
+            self.name,
+            self.msgdef,
         )