Linux/AM3358: Python Issue in SDK 5.x

Brad Griffis

Part Number: AM3358

Tool/software: Linux

AM335x BBB, Linux SDK 5.01

I have a Python script that ran fine in SDK 3.03. It won't work in SDK 5.01. It looks like SDK 3.03 used Python 2 while SDK 5.x has both Python 2 and Python 3. So in that regard I was expecting things to still work. Here's the error that I get:

root@am335x-evm:~# uname -a
Linux am335x-evm 4.14.67-gd315a9bb00 #1 PREEMPT Fri Oct 12 09:30:01 CDT 2018 armv7l GNU/Linux
root@am335x-evm:~# neard
root@am335x-evm:~# test/test-adapter powered nfc0 on
Traceback (most recent call last):
File "test/test-adapter", line 4, in <module>
import dbus
ImportError: No module named dbus

And here's a snippet of the start of that test/test-adapter script:

#!/usr/bin/python

import sys
import dbus
import neardutils

I have tried changing the first line to python3 which actually gets passed this specific error, but it seems to introduce so many other errors that I don't think that's the right solution. Is there something that's missing from the SDK to fully support Python 2 and Python 3?

over 7 years ago

0 Brad Griffis over 7 years ago

TI__Guru*** 125430 points

I managed to get it to work, though I'd still love someone to comment that has deeper knowledge of Python if possible.

I went down the path of changing all the shebangs in various *.py files to reference "python3" instead of "python". There were a bunch of minor formatting changes that needed to be made after that. Things like adding parenthesis to print statements, updating syntax for exception handling, etc. Here's my complete list of changes:

Fullscreen 1641.test-updates.diff Download

diff --git a/home/brad/test/__pycache__/neardutils.cpython-35.pyc b/home/brad/test/__pycache__/neardutils.cpython-35.pyc
new file mode 100644
index 0000000..ef31c77
Binary files /dev/null and b/home/brad/test/__pycache__/neardutils.cpython-35.pyc differ
diff --git a/test/bt-handover b/home/brad/test/bt-handover
index 42d66bf..87ad5d7 100755
--- a/test/bt-handover
+++ b/home/brad/test/bt-handover
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 
 import os
 import sys
diff --git a/test/handover-agent b/home/brad/test/handover-agent
index 7f2ac23..871094a 100755
--- a/test/handover-agent
+++ b/home/brad/test/handover-agent
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 
 import gobject
 
diff --git a/test/monitor-near b/home/brad/test/monitor-near
index f3ad021..216e389 100755
--- a/test/monitor-near
+++ b/home/brad/test/monitor-near
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 
 from __future__ import absolute_import, print_function, unicode_literals
 
diff --git a/test/ndef-agent b/home/brad/test/ndef-agent
index 1cfeb03..937fbfc 100755
--- a/test/ndef-agent
+++ b/home/brad/test/ndef-agent
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 
 import gobject
 
diff --git a/test/neardutils.py b/home/brad/test/neardutils.py
index d93ae63..04af0d5 100644
--- a/test/neardutils.py
+++ b/home/brad/test/neardutils.py
@@ -17,7 +17,7 @@ def find_adapter(pattern=None):
 
 def find_adapter_in_objects(objects, pattern=None):
 	bus = dbus.SystemBus()
-	for path, ifaces in objects.iteritems():
+	for path, ifaces in objects.items():
 		adapter = ifaces.get(ADAPTER_INTERFACE)
 		if adapter is None:
 			continue
@@ -31,7 +31,7 @@ def find_device(pattern=None):
 
 def find_device_in_objects(objects, pattern=None):
 	bus = dbus.SystemBus()
-	for path, ifaces in objects.iteritems():
+	for path, ifaces in objects.items():
 		device = ifaces.get(DEVICE_INTERFACE)
 		if device is None:
 			continue
@@ -45,7 +45,7 @@ def find_tag(pattern=None):
 
 def find_tag_in_objects(objects, pattern=None):
 	bus = dbus.SystemBus()
-	for path, ifaces in objects.iteritems():
+	for path, ifaces in objects.items():
 		tag = ifaces.get(TAG_INTERFACE)
 		if tag is None:
 			continue
@@ -59,7 +59,7 @@ def find_record(pattern=None):
 
 def find_record_in_objects(objects, pattern=None):
 	bus = dbus.SystemBus()
-	for path, ifaces in objects.iteritems():
+	for path, ifaces in objects.items():
 		record = ifaces.get(RECORD_INTERFACE)
 		if record is None:
 			continue
@@ -80,14 +80,14 @@ def dump_record(record_path):
 			val = unicode(properties[key])
 		else:
 			val = str(properties[key])
-		print "      %s = %s" % (key, val)
+		print ("      %s = %s" % (key, val))
 
 def dump_all_records(path):
 	bus = dbus.SystemBus()
 	om = dbus.Interface(bus.get_object(SERVICE_NAME, "/"),
 					"org.freedesktop.DBus.ObjectManager")
 	objects = om.GetManagedObjects()
-	for path, interfaces in objects.iteritems():
+	for path, interfaces in objects.items():
 		if RECORD_INTERFACE not in interfaces:
 			continue
 
diff --git a/test/test-adapter b/home/brad/test/test-adapter
index 173519e..63d34f8 100755
--- a/test/test-adapter
+++ b/home/brad/test/test-adapter
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 
 import sys
 import dbus
@@ -70,8 +70,8 @@ if (sys.argv[1] == "powered"):
 			value = dbus.Boolean(sys.argv[3])
 		try:
 			adapter.Set("org.neard.Adapter", "Powered", value)
-		except dbus.DBusException, error:
-			print "%s: %s" % (error._dbus_error_name, error.message)
+		except dbus.DBusException as error:
+			print ("%s: %s" % (error._dbus_error_name, error.message))
 	sys.exit(0)
 
 if (sys.argv[1] == "poll"):
@@ -90,14 +90,14 @@ if (sys.argv[1] == "poll"):
 
 			try:
 				adapter.StartPollLoop(mode)
-			except dbus.DBusException, error:
-				print "%s: %s" % (error._dbus_error_name, error.message)
+			except dbus.DBusException as error:
+				print ("%s: %s" % (error._dbus_error_name, error.message))
 
 		elif (sys.argv[3] == "off"):
 			try:
 				adapter.StopPollLoop()
-			except dbus.DBusException, error:
-				print "%s: %s" % (error._dbus_error_name, error.message)
+			except dbus.DBusException as error:
+				print ("%s: %s" % (error._dbus_error_name, error.message))
 
 		else:
 			usage()
diff --git a/test/test-device b/home/brad/test/test-device
index 1c90ef1..1ca894d 100755
--- a/test/test-device
+++ b/home/brad/test/test-device
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 
 import sys
 import dbus
diff --git a/test/test-tag b/home/brad/test/test-tag
index cb2c9e8..7e67950 100755
--- a/test/test-tag
+++ b/home/brad/test/test-tag
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 
 import sys
 import dbus
@@ -46,7 +46,7 @@ if (len(sys.argv) < 2):
 if (sys.argv[1] == "list"):
 	if (len(sys.argv) < 3):
 		objects = neardutils.get_managed_objects()
-		for path, interfaces in objects.iteritems():
+		for path, interfaces in objects.items():
 			if "org.neard.Tag" not in interfaces:
 				continue
 
@@ -70,7 +70,7 @@ if (sys.argv[1] == "list"):
 if (sys.argv[1] == "dump"):
 	if (len(sys.argv) < 3):
 		objects = neardutils.get_managed_objects()
-		for path, interfaces in objects.iteritems():
+		for path, interfaces in objects.items():
 			if "org.neard.Tag" not in interfaces:
 				continue
 
@@ -127,7 +127,7 @@ def write_uri(args):
 		data["Type"] = "URI"
 		data["URI"] = args[0]
 
-	print data
+	print( data )
 
 	tag.Write(data)
 
@@ -169,7 +169,7 @@ if (sys.argv[1] == "write"):
 	sys.exit(0)
 
 if (sys.argv[1] == "deactivate"):
-	print sys.argv[2]
+	print( sys.argv[2] )
 	if (len(sys.argv) != 2):
 		tag = neardutils.find_tag(sys.argv[2])
 		tag.Deactivate()

0 RonB over 7 years ago in reply to Brad Griffis

TI__Mastermind 30566 points

Brad,

Sorry, I'm not a python expert. In some of our docs for python3, we list the following as the way to switch from the default 2 to 3 with these commands:

root@am57xx-evm:/usr/bin# ln -sf python3 python.python
root@am57xx-evm:/usr/bin# ln -sf python3-config python-config.python

I wonder if they would have provided a simpler fix for you.

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Linux/AM3358: Python Issue in SDK 5.x