Remove support for old Python versions

.appveyor.yml

@@ -3,14 +3,10 @@ environment:
 
     # For Python versions available on Appveyor, see
     # https://www.appveyor.com/docs/windows-images-software/#python
-    # Python pre-2.7 and 3.0-3.4 have reached EOL
+    # Only Python 3.6+ is supported
 
-    - PYTHON: "C:\\Python27"
-    - PYTHON: "C:\\Python35"
     - PYTHON: "C:\\Python36"
     - PYTHON: "C:\\Python37"
-    - PYTHON: "C:\\Python27-x64"
-    - PYTHON: "C:\\Python35-x64"
     - PYTHON: "C:\\Python36-x64"
     - PYTHON: "C:\\Python37-x64"
 

.travis.yml

@@ -8,15 +8,12 @@ cache:
   - "$HOME/.cache/pip"
 
 python:
-  # CPython; versions pre-2.7 and 3.0-3.5 have reached EOL
-  - "2.7"
+  # CPython; only 3.6 is supported
   - "3.6"
   - "3.7"
   - 3.8-dev
   - nightly
   # PyPy:
-  - pypy # Python 2.7
-  - pypy3.5 # Python 3.5
   - pypy3
 
 env:

README.rst

@@ -37,15 +37,15 @@ Python developers; providing common abstractions to
 different hardware devices, and a suite of utilities for sending and receiving
 messages on a can bus.
 
-The library supports Python 2.7, Python 3.5+ as well as PyPy 2 & 3 and runs
+The library currently supports Python 3.6+ as well as PyPy 3 and runs
 on Mac, Linux and Windows.
 
 ==================  ===========
 Library Version      Python
 ------------------  -----------
   2.x                 2.6+, 3.4+
   3.x                 2.7+, 3.5+
-  4.x (expected)      3.6+
+  4.x                 3.6+
 ==================  ===========
 
 

can/__init__.py

@@ -4,8 +4,6 @@
 ``can`` is an object-orient Controller Area Network (CAN) interface module.
 """
 
-from __future__ import absolute_import
-
 import logging
 
 __version__ = "3.2.0"
@@ -22,11 +20,7 @@ class CanError(IOError):
     pass
 
 
-from .listener import Listener, BufferedReader, RedirectReader
-try:
-    from .listener import AsyncBufferedReader
-except ImportError:
-    pass
+from .listener import Listener, BufferedReader, RedirectReader, AsyncBufferedReader
 
 from .io import Logger, Printer, LogReader, MessageSync
 from .io import ASCWriter, ASCReader

can/broadcastmanager.py

@@ -16,7 +16,7 @@
 log = logging.getLogger('can.bcm')
 
 
-class CyclicTask(object):
+class CyclicTask:
     """
     Abstract Base for all cyclic tasks.
     """

can/bus.py

@@ -4,8 +4,6 @@
 Contains the ABC bus implementation and its documentation.
 """
 
-from __future__ import print_function, absolute_import
-
 from abc import ABCMeta, abstractmethod
 import logging
 import threading
@@ -26,7 +24,7 @@ class BusState(Enum):
     ERROR = auto()
 
 
-class BusABC(object):
+class BusABC(metaclass=ABCMeta):
     """The CAN Bus Abstract Base Class that serves as the basis
     for all concrete interfaces.
 
@@ -403,5 +401,3 @@ def _detect_available_configs():
                  for usage in the interface's bus constructor.
         """
         raise NotImplementedError()
-
-    __metaclass__ = ABCMeta

can/interface.py

@@ -6,8 +6,6 @@
 CyclicSendTasks.
 """
 
-from __future__ import absolute_import, print_function
-
 import sys
 import importlib
 import logging
@@ -18,10 +16,6 @@
 from .util import load_config
 from .interfaces import BACKENDS
 
-# Required by "detect_available_configs" for argument interpretation
-if sys.version_info.major > 2:
-    basestring = str
-
 log = logging.getLogger('can.interface')
 log_autodetect = log.getChild('detect_available_configs')
 
@@ -144,10 +138,9 @@ def detect_available_configs(interfaces=None):
 
     # Figure out where to search
     if interfaces is None:
-        # use an iterator over the keys so we do not have to copy it
-        interfaces = BACKENDS.keys()
-    elif isinstance(interfaces, basestring):
-        interfaces = [interfaces, ]
+        interfaces = BACKENDS
+    elif isinstance(interfaces, str):
+        interfaces = (interfaces, )
     # else it is supposed to be an iterable of strings
 
     result = []

can/interfaces/canalystii.py

@@ -1,3 +1,5 @@
+# coding: utf-8
+
 from ctypes import *
 import logging
 import platform

can/interfaces/iscan.py

@@ -4,8 +4,6 @@
 Interface for isCAN from Thorsis Technologies GmbH, former ifak system GmbH.
 """
 
-from __future__ import absolute_import, division
-
 import ctypes
 import time
 import logging

can/interfaces/ixxat/canlib.py

@@ -13,8 +13,6 @@
 
 """
 
-from __future__ import absolute_import, division
-
 import ctypes
 import functools
 import logging
@@ -32,11 +30,7 @@
 
 log = logging.getLogger('can.ixxat')
 
-try:
-    # since Python 3.3
-    from time import perf_counter as _timer_function
-except ImportError:
-    from time import clock as _timer_function
+from time import perf_counter as _timer_function
 
 # Hack to have vciFormatError as a free function, see below
 vciFormatError = None

can/interfaces/kvaser/canlib.py

@@ -8,8 +8,6 @@
 Copyright (C) 2010 Dynamic Controls
 """
 
-from __future__ import absolute_import
-
 import sys
 import time
 import logging

can/interfaces/pcan/pcan.py

@@ -4,8 +4,6 @@
 Enable basic CAN over a PCAN USB device.
 """
 
-from __future__ import absolute_import, print_function, division
-
 import logging
 import sys
 import time
@@ -16,8 +14,8 @@
 from can.util import len2dlc, dlc2len
 from .basic import *
 
-boottimeEpoch = 0
 try:
+    # use the "uptime" library if available
     import uptime
     import datetime
     boottimeEpoch = (uptime.boottime() - datetime.datetime.utcfromtimestamp(0)).total_seconds()
@@ -39,13 +37,6 @@
         # Use polling instead
         HAS_EVENTS = False
 
-try:
-    # new in 3.3
-    timeout_clock = time.perf_counter
-except AttributeError:
-    # deprecated in 3.3
-    timeout_clock = time.clock
-
 # Set up logging
 log = logging.getLogger('can.pcan')
 
@@ -277,7 +268,7 @@ def _recv_internal(self, timeout):
             timeout_ms = int(timeout * 1000) if timeout is not None else INFINITE
         elif timeout is not None:
             # Calculate max time
-            end_time = timeout_clock() + timeout
+            end_time = time.perf_counter() + timeout
 
         #log.debug("Trying to read a msg")
 
@@ -293,7 +284,7 @@ def _recv_internal(self, timeout):
                     val = WaitForSingleObject(self._recv_event, timeout_ms)
                     if val != WAIT_OBJECT_0:
                         return None, False
-                elif timeout is not None and timeout_clock() >= end_time:
+                elif timeout is not None and time.perf_counter() >= end_time:
                     return None, False
                 else:
                     result = None

can/interfaces/serial/serial_can.py

@@ -7,8 +7,6 @@
 recording CAN traces.
 """
 
-from __future__ import absolute_import, division
-
 import logging
 import struct
 

can/interfaces/slcan.py

@@ -9,8 +9,6 @@
 
 """
 
-from __future__ import absolute_import
-
 import time
 import logging
 

can/interfaces/socketcan/__init__.py

@@ -4,4 +4,4 @@
 See: https://www.kernel.org/doc/Documentation/networking/can.txt
 """
 
-from can.interfaces.socketcan.socketcan import SocketcanBus, CyclicSendTask, MultiRateCyclicSendTask
+from .socketcan import SocketcanBus, CyclicSendTask, MultiRateCyclicSendTask

can/interfaces/socketcan/socketcan.py

@@ -29,42 +29,6 @@
     pack_filters, find_available_interfaces, error_code_to_str
 
 
-try:
-    socket.CAN_BCM
-except AttributeError:
-    HAS_NATIVE_SUPPORT = False
-else:
-    HAS_NATIVE_SUPPORT = True
-
-
-if not HAS_NATIVE_SUPPORT:
-    def check_status(result, function, arguments):
-        if result < 0:
-            raise can.CanError(error_code_to_str(ctypes.get_errno()))
-        return result
-
-    try:
-        libc = ctypes.CDLL(ctypes.util.find_library("c"), use_errno=True)
-        libc.bind.errcheck = check_status
-        libc.connect.errcheck = check_status
-        libc.sendto.errcheck = check_status
-        libc.recvfrom.errcheck = check_status
-    except:
-        log.warning("libc is unavailable")
-        libc = None
-
-    def get_addr(sock, channel):
-        """Get sockaddr for a channel."""
-        if channel:
-            data = struct.pack("16si", channel.encode(), 0)
-            res = fcntl.ioctl(sock, SIOCGIFINDEX, data)
-            idx, = struct.unpack("16xi", res)
-        else:
-            # All channels
-            idx = 0
-        return struct.pack("HiLL", AF_CAN, idx, 0, 0)
-
-
 # Setup BCM struct
 def bcm_header_factory(fields, alignment=8):
     curr_stride = 0
@@ -262,11 +226,7 @@ def dissect_can_frame(frame):
 def create_bcm_socket(channel):
     """create a broadcast manager socket and connect to the given interface"""
     s = socket.socket(PF_CAN, socket.SOCK_DGRAM, CAN_BCM)
-    if HAS_NATIVE_SUPPORT:
-        s.connect((channel,))
-    else:
-        addr = get_addr(s, channel)
-        libc.connect(s.fileno(), addr, len(addr))
+    s.connect((channel,))
     return s
 
 
@@ -421,12 +381,7 @@ def bind_socket(sock, channel='can0'):
         If the specified interface isn't found.
     """
     log.debug('Binding socket to channel=%s', channel)
-    if HAS_NATIVE_SUPPORT:
-        sock.bind((channel,))
-    else:
-        # For Python 2.7
-        addr = get_addr(sock, channel)
-        libc.bind(sock.fileno(), addr, len(addr))
+    sock.bind((channel,))
     log.debug('Bound socket.')
 
 
@@ -444,22 +399,8 @@ def capture_message(sock, get_channel=False):
     # Fetching the Arb ID, DLC and Data
     try:
         if get_channel:
-            if HAS_NATIVE_SUPPORT:
-                cf, addr = sock.recvfrom(CANFD_MTU)
-                channel = addr[0] if isinstance(addr, tuple) else addr
-            else:
-                data = ctypes.create_string_buffer(CANFD_MTU)
-                addr = ctypes.create_string_buffer(32)
-                addrlen = ctypes.c_int(len(addr))
-                received = libc.recvfrom(sock.fileno(), data, len(data), 0,
-                                         addr, ctypes.byref(addrlen))
-                cf = data.raw[:received]
-                # Figure out the channel name
-                family, ifindex = struct.unpack_from("Hi", addr.raw)
-                assert family == AF_CAN
-                data = struct.pack("16xi", ifindex)
-                res = fcntl.ioctl(sock, SIOCGIFNAME, data)
-                channel = ctypes.create_string_buffer(res).value.decode()
+            cf, addr = sock.recvfrom(CANFD_MTU)
+            channel = addr[0] if isinstance(addr, tuple) else addr
         else:
             cf = sock.recv(CANFD_MTU)
             channel = None
@@ -634,13 +575,7 @@ def _send_once(self, data, channel=None):
         try:
             if self.channel == "" and channel:
                 # Message must be addressed to a specific channel
-                if HAS_NATIVE_SUPPORT:
-                    sent = self.socket.sendto(data, (channel, ))
-                else:
-                    addr = get_addr(self.socket, channel)
-                    sent = libc.sendto(self.socket.fileno(),
-                                       data, len(data), 0,
-                                       addr, len(addr))
+                sent = self.socket.sendto(data, (channel, ))
             else:
                 sent = self.socket.send(data)
         except socket.error as exc:
@@ -722,7 +657,7 @@ def receiver(event):
         bind_socket(receiver_socket, 'vcan0')
         print("Receiver is waiting for a message...")
         event.set()
-        print("Receiver got: ", capture_message(receiver_socket))
+        print(f"Receiver got: {capture_message(receiver_socket)}")
 
     def sender(event):
         event.wait()

can/interfaces/socketcan/utils.py

@@ -67,6 +67,7 @@ def find_available_interfaces():
         log.debug("find_available_interfaces(): detected: %s", interface_names)
         return filter(_PATTERN_CAN_INTERFACE.match, interface_names)
 
+
 def error_code_to_str(code):
     """
     Converts a given error code (errno) to a useful and human readable string.

can/interfaces/systec/ucanbus.py

@@ -16,6 +16,7 @@ class Ucan(UcanServer):
     """
     Wrapper around UcanServer to read messages with timeout using events.
     """
+
     def __init__(self):
         super(Ucan, self).__init__()
         self._msg_received_event = Event()