Commit to Python3 only

Remove py23 and reimplement associated functions in Python 3.

Author: Araneidae

src/cothread/cadef.py

@@ -47,7 +47,6 @@
 
 import ctypes
 from .load_ca import libca
-from . import py23
 
 
 
@@ -187,13 +186,31 @@ def convert_py_object(object, function, args):
 #   libca function definitions
 
 
+# String encoding and decoding helpers for ctypes string arguments
+
+class auto_encode(ctypes.c_char_p):
+    @classmethod
+    def from_param(cls, value):
+        if value is None:
+            return value
+        else:
+            return value.encode('UTF-8')
+
+def auto_decode(result, func, args):
+    if result is None:
+        return result
+    else:
+        return result.decode('UTF-8', 'replace')
+
+
+
 #   error_message = ca_message(status_code)
 #
 # Converts channel access status code (an int) into a printable error message.
 ca_message = libca.ca_message
 ca_message.argtypes = [ctypes.c_long]
 ca_message.restype = ctypes.c_char_p
-ca_message.errcheck = py23.auto_decode
+ca_message.errcheck = auto_decode
 
 
 #   channel_name = ca_name(channel)
@@ -202,7 +219,7 @@ def convert_py_object(object, function, args):
 ca_name = libca.ca_name
 ca_name.argtypes = [ctypes.c_void_p]
 ca_name.restype = ctypes.c_char_p
-ca_name.errcheck = py23.auto_decode
+ca_name.errcheck = auto_decode
 
 
 #   @exception_handler
@@ -247,7 +264,7 @@ def convert_py_object(object, function, args):
 # recovered by calling ca_puser(channel_id).
 ca_create_channel = libca.ca_create_channel
 ca_create_channel.argtypes = [
-    py23.auto_encode, connection_handler, ctypes.py_object,
+    auto_encode, connection_handler, ctypes.py_object,
     ctypes.c_int, ctypes.c_void_p]
 ca_create_channel.errcheck = expect_ECA_NORMAL
 
@@ -401,7 +418,7 @@ def convert_py_object(object, function, args):
 ca_host_name = libca.ca_host_name
 ca_host_name.argtypes = [ctypes.c_void_p]
 ca_host_name.restype = ctypes.c_char_p
-ca_host_name.errcheck = py23.auto_decode
+ca_host_name.errcheck = auto_decode
 
 
 #   read = ca_read_access(channel_id)

src/cothread/catools.py

@@ -46,8 +46,6 @@
 See the documentation for the individual functions for more details on using
 them.'''
 
-from __future__ import print_function
-
 import os
 import sys
 import atexit
@@ -58,7 +56,6 @@
 from . import cothread
 from . import cadef
 from . import dbr
-from . import py23
 
 from .dbr import *
 from .cadef import *
@@ -154,7 +151,7 @@ def ca_timeout(event, timeout, name):
     try:
         return event.Wait(timeout)
     except cothread.Timedout as timeout:
-        py23.raise_from(ca_nothing(name, cadef.ECA_TIMEOUT), timeout)
+        raise ca_nothing(name, cadef.ECA_TIMEOUT) from timeout
 
 
 # ----------------------------------------------------------------------------
@@ -371,7 +368,7 @@ def __signal(self, value):
                 if isinstance(value, tuple):
                     # This should only happen if the asynchronous callback
                     # caught an exception for us to re-raise here.
-                    py23.raise_with_traceback(value)
+                    raise value[1].with_traceback(value[2])
                 else:
                     self.callback(value)
             except:

src/cothread/coselect.py

@@ -29,8 +29,6 @@
 '''Support for cooperative select functions.  Replaces the functionality of
 the standard select module.'''
 
-from __future__ import absolute_import
-
 import select as _select
 import cothread
 

src/cothread/cothread.py

@@ -66,8 +66,6 @@
 # It might be worth taking a close look at:
 #   http://wiki.secondlife.com/wiki/Eventlet
 
-from __future__ import print_function
-
 import sys
 import os
 import time
@@ -77,7 +75,6 @@
 import threading
 
 from . import _coroutine
-from . import py23
 
 if os.environ.get('COTHREAD_CHECK_STACK'):
     _coroutine.enable_check_stack(True)
@@ -442,7 +439,7 @@ def poll_scheduler(self, ready_list):
 
         if isinstance(result, tuple):
             # This case arises if we are main and the scheduler just died.
-            py23.raise_with_traceback(result)
+            raise result[1].with_traceback(result[2])
         else:
             return result
 
@@ -492,7 +489,7 @@ def wait_until(self, until, suspend_queue, wakeup):
             # to die.  Make sure our wakeup is cancelled, and then
             # re-raise the offending exception.
             wakeup.wakeup(result)
-            py23.raise_with_traceback(result)
+            raise result[1].with_traceback(result[2])
         else:
             return result == _WAKEUP_TIMEOUT
 
@@ -711,7 +708,7 @@ def Wait(self, timeout = None):
             try:
                 # Re-raise the exception that actually killed the task here
                 # where it can be received by whoever waits on the task.
-                py23.raise_with_traceback(result)
+                raise result[1].with_traceback(result[2])
             finally:
                 # In this case result and self.__result contain a traceback.  To
                 # avoid circular references which will delay garbage collection,
@@ -1018,7 +1015,7 @@ def do_action():
         if ok:
             return result
         else:
-            py23.raise_with_traceback(result)
+            raise result[1].with_traceback(result[2])
 
         # Note: raising entire stack backtrace context might be dangerous, need
         # to think about this carefully, particularly if the corresponding stack

src/cothread/dbr.py

@@ -37,7 +37,6 @@
 import datetime
 
 from . import cadef
-from . import py23
 
 
 __all__ = [
@@ -215,6 +214,11 @@ class ca_timestamp(ctypes.Structure):
 # ----------------------------------------------------------------------------
 #   DBR type definitions
 
+# Default string decoding method
+def decode(s):
+    return s.decode('UTF-8', 'replace')
+
+
 # All the following types are used to overlay dbr data returned from channel
 # access or passed into channel access.
 
@@ -241,7 +245,7 @@ def copy_attributes_ctrl(self, other):
     other.status = self.status
     other.severity = self.severity
 
-    other.units = py23.decode(ctypes.string_at(self.units))
+    other.units = decode(ctypes.string_at(self.units))
     other.upper_disp_limit = self.upper_disp_limit
     other.lower_disp_limit = self.lower_disp_limit
     other.upper_alarm_limit = self.upper_alarm_limit
@@ -431,7 +435,7 @@ def copy_attributes(self, other):
         other.status = self.status
         other.severity = self.severity
         other.enums = [
-            py23.decode(ctypes.string_at(s))
+            decode(ctypes.string_at(s))
             for s in self.raw_strs[:self.no_str]]
 
 class dbr_ctrl_char(ctypes.Structure):
@@ -631,10 +635,9 @@ def _datatype_to_dbr(datatype):
         # with filtering through our array of acceptable types.
         return NumpyCharCodeToDbr[numpy.dtype(datatype).char]
     except Exception as error:
-        py23.raise_from(
-            InvalidDatatype(
-                'Datatype "%s" not supported for channel access' % datatype),
-            error)
+        raise InvalidDatatype(
+            'Datatype "%s" not supported for channel access' % datatype
+        ) from error
 
 def _type_to_dbrcode(datatype, format):
     '''Converts a datatype and format request to a dbr value, or raises an
@@ -704,7 +707,7 @@ def _string_at(raw_value, count):
 
 # Conversion from char array to strings
 def _convert_char_str(raw_dbr, count):
-    return ca_str(py23.decode(_string_at(raw_dbr.raw_value, count)))
+    return ca_str(decode(_string_at(raw_dbr.raw_value, count)))
 
 # Conversion from char array to bytes strings
 def _convert_char_bytes(raw_dbr, count):
@@ -717,9 +720,9 @@ def _convert_char_unicode(raw_dbr, count):
 
 # Arrays of standard strings.
 def _convert_str_str(raw_dbr, count):
-    return ca_str(py23.decode(_make_strings(raw_dbr, count)[0]))
+    return ca_str(decode(_make_strings(raw_dbr, count)[0]))
 def _convert_str_str_array(raw_dbr, count):
-    strings = [py23.decode(s) for s in _make_strings(raw_dbr, count)]
+    strings = [decode(s) for s in _make_strings(raw_dbr, count)]
     return _string_array(strings, count, str_char_code)
 
 # Arrays of bytes strings.

src/cothread/load_ca.py

@@ -32,8 +32,6 @@
 # This file can also be run as a standalone script to discover the path to
 # libca.
 
-from __future__ import print_function
-
 import ctypes
 import platform
 import os

src/cothread/py23.py

@@ -2,8 +2,6 @@
 
 # Simple tool for viewing the chain of PV dependencies.
 
-from __future__ import print_function
-
 import sys
 import re
 import os

src/cothread/tools/pvtree.py

@@ -13,7 +13,6 @@
 from cothread import coselect, cosocket
 from cothread import Spawn, Sleep, Event, Timedout
 from cothread.load_ca import epics_host_arch
-from cothread import py23
 
 __all__ = [
     'IOCTestCaseMixin',
@@ -292,7 +291,7 @@ def _tty_read(self):
         # seperate cothread
         try:
             while True:
-                T = py23.decode(self._tty.read(1024))
+                T = self._tty.read(1024).decode('UTF-8', 'replace')
                 if not T:
                     return
                 self._tty_in += T