I am writing a GUI in Linux using Kivy and Python. The program should detect a USB device and using the device to program an image to a target. Here are a snippet of my code:
These are the codes I am trying to detect USB device. This is on a file, let's call it A.py.
busses = usb.busses()
for bus in busses:
devices = bus.devices
for dev in devices:
if (dev.idVendor == vendor and dev.idProduct == product):
obj = ProgJTAG.ProgJTAG(bus.dirname,dev.filename, dev.idVendor, dev.idProduct, dev)
break
When I ran the program, assertion error occured in creating an instance of ProgJTAG. This is defined in a separate file ProgJTAG.py as follows:
class ProgJTAG(BoxLayout):
usb_bus = StringProperty('')
usb_dev = StringProperty('')
usb_vendor = StringProperty('')
usb_product = StringProperty('')
def __init__(self, _usb_bus, _usb_dev, _usb_vendor, _usb_product, dev):
super(ProgJTAG, self).__init__()
self.usb_bus = _usb_bus
self.usb_dev = _usb_dev
self.usb_vendor = str(_usb_vendor)
self.usb_product = str(_usb_product)
self.bind(usb_bus=self.usb_bus)
self.bind(usb_dev=self.usb_bus)
self.bind(usb_vendor=self.usb_bus)
self.bind(usb_product=self.usb_bus)
The error occur from the line self.bind(usb_bus=self.usb_bus). The error message is File "_event.pyx", kivy._event.EventDispatcher.bind(kivy/_event.c:5536)
AssertionError: '' is not callable
Q1. Can anyone help what the assertion means?
Q2. I noticed that the _usb_bus and _usb_dev are empty string. Is this assertion caused by the fact that the _usb_bus and _usb_dev are empty string property hence not callable?
Yes, when you bind you must pass a function because the binding will try to call it later.
Related
Here is my python code that I am using. I am trying to use a wii remote to trigger a buzzer. I thought this would be an interesting use for my old wii remote. The code that interacts with the buzzer works fine because I used an example script to test it. However, when I try and run it I keep getting this one error (see bottom). I am new to python and would appreciate any help.
import cwiid
from gpiozero import LED
import time
import os
Buzzer1 = LED(17)
Buzzer2 = LED(27)
def ConnectRemote():
os.system("rfkill unblock bluetooth")
print 'Press 1+2 On The Remote...'
global wm
wm = wiid.Wiimote()
print 'Connection Established!\n'
wm.led = 1
wm.rumble = 1
time.sleep(0.25)
wm.rumble = 0
time.sleep(0.5)
wm.rpt_mode = cwiid.RPT_BTN
def TryToConnect():
while True:
ConnectRemote()
break
while True:
buttons = wm.state['buttons']
#shutdown function using plus and minus buttons
if (buttons - cwiid.BTN_PLUS - cwiid.BTN_MINUS == 0):
print '\nClosing Connection To Wiimote'
wm.rumble = 1
time.sleep(0.25)
wm.rumble = 0
os.system("rfkill block bluetooth")
TryToConnect()
if (buttons & cwiid.BTN_A):
print 'Buzzer On'
Buzzer1.on()
Buzzer2.on()
else:
Buzzer1.off()
Buzzer2.off()
and yet I keep getting an error of
Traceback (most recent call last):
File "WiimoteLEDs.py", line 36, in <module>
buttons = wm.state['buttons']
NameError: global name 'wm' is not defined
Can anyone help? Thanks in advance
I think you should initialized variable wm before using this variable in function.
This bug is related to 'Global name not defined'
I am running a rosnode with a kalman filter running. The kalman filter is an object with states that get updated as time plays out. Conventionally, a ros node has a run(self) method that runs at a specified frequency using the while condition
while not rospy.is_shutdown():
do this
Going through each loop my kalman filter object updates. I just want to be able to save the kalman filter object when the node is shutdown either some external condition or when the user presses ctrl+C. I am not able to do this. In the run(self) method, I tried
while not rospy.is_shutdown():
do this
# save in file
output = pathlib.Path('path/to/location')
results_path = output.with_suffix('.npz')
with open(results_path, 'xb') as results_file:
np.savez(results_file,kfObj=kf_list)
But it has not worked. Is it not executing the save command? If ctrl+C is pressed does it stop short of executing it? Whats the way to do it?
Check out the atexit module:
http://docs.python.org/library/atexit.html
import atexit
def exit_handler():
output = pathlib.Path('path/to/location')
results_path = output.with_suffix('.npz')
with open(results_path, 'xb') as results_file:
np.savez(results_file,kfObj=kf_list
atexit.register(exit_handler)
Just be aware that this works great for normal termination of the script, but it won't get called in all cases (e.g. fatal internal errors).
Why not try the following python example class structure engaging shutdown hooks :
import rospy
class Hardware_Interface:
def __init__(self, selectedBoard):
...
# Housekeeping, cleanup at the end
rospy.on_shutdown(self.shutdown)
# Get the connection settings from the parameter server
self.port = rospy.get_param("~"+self.board+"-port", "/dev/ttyACM0")
# Get the prefix
self.prefix = rospy.get_param("~"+self.board+"-prefix", "travel")
# Overall loop rate
self.rate = int(rospy.get_param("~rate", 5))
self.period = rospy.Duration(1/float(self.rate))
...
def shutdown(self):
rospy.loginfo("Shutting down Hardware Interface Node...")
try:
rospy.loginfo("Stopping the robot...")
self.controller.send(0, 0, 0, 0)
#self.cmd_vel_pub.publish(Twist())
rospy.sleep(2)
except:
rospy.loginfo("Cannot stop!")
try:
self.controller.close()
except:
pass
finally:
rospy.loginfo("Serial port closed.")
os._exit(0)
This just an extract from a personal script, please modify it to your needs. I imagine that the on_shutdown will do the trick. Another similar approach comes from my friends in the Robot Ignite Academy in The Construct and seems like that
#!/usr/bin/env python
import rospy
from geometry_msgs.msg import Twist
class my_class():
def __init__(self):
...
self.cmd = Twist()
self.ctrl_c = False
self.rate = rospy.Rate(10) # 10hz
rospy.on_shutdown(self.shutdownhook)
def publish_once_in_cmd_vel(self):
while not self.ctrl_c:
...
def shutdownhook(self):
# works better than the rospy.is_shutdown()
self.ctrl_c = True
def move_something(self, linear_speed=0.2, angular_speed=0.2):
self.cmd.linear.x = linear_speed
self.cmd.angular.z = angular_speed
self.publish_once_in_cmd_vel()
if __name__ == '__main__':
rospy.init_node('class_test', anonymous=True)
...
This is obviously a sample of their code (for more please join the academy)
Hello I want to know how to load a Dialog Topic file using python.
I made sure that the file path is right, but it keeps saying that it isn't. I have also used the tutorials in NAO 2.1's documentation ALDialog and ALModule
Please send me a code that works or tell me the error. I tried using the following code:
NAO_IP = "nao.local"
dialog_p = None
ModuleInstance = None
class NaoFalanteModule(ALModule):
def __init__(self, name):
ALModule.__init__(self, name)
self.tts = ALProxy("ALTextToSpeech")
self.tts.setLanguage("Brazilian")
global dialog_p
try:
dialog_p = ALProxy("ALDialog")
except Exception, e:
print "Error dialog"
print str(e)
exit(1)
dialog_p.setLanguage("Brazilian")
self.naoAlc()
def naoAlc(self):
topf_path = "/simpleTestes/diaSimples/testeSimples_ptb.top"
topf_path = topf_path.decode("utf-8")
topic = dialog_p.loadTopic(topf_path.encode("utf-8"))
# Start dialog
dialog_p.subscribe("NaoFalanteModule")
dialog_p.activateTopic(topic)
raw_input(u"Press 'Enter' to exit.")
dialog_p.unload(topic)
dialog_p.unsubscribe
def main():
parser = OptionParser()
parser.add_option("--pip",
help="Parent broker port. The IP address or your robot",
dest="pip")
parser.add_option("--pport",
help="Parent broker port. The port NAOqi is listening to",
dest="pport",
type="int")
parser.set_defaults(
pip=NAO_IP,
pport=9559)
(opts, args_) = parser.parse_args()
pip = opts.pip
pport = opts.pport
myBroker = ALBroker("myBroker",
"0.0.0.0",
0,
pip,
pport)
global ModuleInstance
ModuleInstance = NaoFalanteModule("ModuleInstance")
try:
while True:
time.sleep(1)
except KeyboardInterrupt:
printI tried using the following code:
print "Interrupted by user, shutting down"
myBroker.shutdown()
sys.exit(0)
if __name__ == "__main__":
main()
The path to the topic needs to be the absolute path to that file, whereas you're passing a relative path compared to your current execution directory. The reason is that ALDialog is a separate service running in it's own process and knows nothing about the execution context of whoever is calling it.
And the program .top file must be uploaded to the robot using Choregraphe.
So, your absolute path in this case might be something like
topf_path = "/home/nao/simpleTestes/diaSimples/testeSimples_ptb.top"
... or if you want to be a bit cleaner, if you know your script is being executed at the root of your application package, use os.path:
topf_path = os.path.abspath("diaSimples/testeSimples_ptb.top")
I am trying to get ryu to run, especially the topology discovery.
Now I am running the demo application for that under ryu/topology/dumper.py, which is supposed to dump all topology events. I am in the ryu/topology direcory and run it using ryu-manager dumper.py. The version of ryu-manager is 2.23.2.
Shortly after starting it gives me this error:
/usr/local/lib/python2.7/dist-packages/ryu/topology/switches.py:478: UserWarning:
Datapath#ports is kept for compatibility with the previous openflow versions (< 1.3).
This not be updated by EventOFPPortStatus message. If you want to be updated,
you can use 'ryu.controller.dpset' or 'ryu.topology.switches'.
for port in dp.ports.values():
What's really weird to me is that it recommends to use ryu.topology.switches, but that error is triggered by line 478 of that very file!
The function in question is this:
class Switches(app_manager.RyuApp):
OFP_VERSIONS = [ofproto_v1_0.OFP_VERSION, ofproto_v1_2.OFP_VERSION,
ofproto_v1_3.OFP_VERSION, ofproto_v1_4.OFP_VERSION]
_EVENTS = [event.EventSwitchEnter, event.EventSwitchLeave,
event.EventPortAdd, event.EventPortDelete,
event.EventPortModify,
event.EventLinkAdd, event.EventLinkDelete]
DEFAULT_TTL = 120 # unused. ignored.
LLDP_PACKET_LEN = len(LLDPPacket.lldp_packet(0, 0, DONTCARE_STR, 0))
LLDP_SEND_GUARD = .05
LLDP_SEND_PERIOD_PER_PORT = .9
TIMEOUT_CHECK_PERIOD = 5.
LINK_TIMEOUT = TIMEOUT_CHECK_PERIOD * 2
LINK_LLDP_DROP = 5
#...
def _register(self, dp):
assert dp.id is not None
self.dps[dp.id] = dp
if dp.id not in self.port_state:
self.port_state[dp.id] = PortState()
for port in dp.ports.values(): # THIS LINE
self.port_state[dp.id].add(port.port_no, port)
Has anyone else encountered this problem before? How can I fix it?
I ran into the same issue (depending on your application, maybe it's not a problem, just a warning that you can ignore). Here is what I figured out after a find . -type f | xargs grep "ports is kept"
This warning is triggered in ryu.topology.switches, by a call to _get_ports() in class Datapath of file ryu/controller/controller.py.
class Datapath(ofproto_protocol.ProtocolDesc):
#......
def _get_ports(self):
if (self.ofproto_parser is not None and
self.ofproto_parser.ofproto.OFP_VERSION >= 0x04):
message = (
'Datapath#ports is kept for compatibility with the previous '
'openflow versions (< 1.3). '
'This not be updated by EventOFPPortStatus message. '
'If you want to be updated, you can use '
'\'ryu.controller.dpset\' or \'ryu.topology.switches\'.'
)
warnings.warn(message, stacklevel=2)
return self._ports
def _set_ports(self, ports):
self._ports = ports
# To show warning when Datapath#ports is read
ports = property(_get_ports, _set_ports)
My understanding is that if the warning is from ryu.topology.switches or ryu.controller.dpset, you can ignore it; because those two classes handle the event for you. But if you use Datapath directly, port status is not updated automatically. Anyone correct me if I'm wrong.
class Switches(app_manager.RyuApp):
#......
#set_ev_cls(ofp_event.EventOFPPortStatus, MAIN_DISPATCHER)
def port_status_handler(self, ev):
I have encountered that problem before but I just ignored it and so far every thing has been working as it was expected.
If you are trying to learn the topology I would recommend using ryu.topology.api. i.e.
from ryu.topology.api import get_switch, get_link
There is this tutorial. However there are some of the stuff missing.
Here is what I have so far: Controller.py
In the Controller.py the two functions get_switch(self, None) and get_link(self, None) would give you list of links and switches.
I'm trying to use the Python package ComplexNetworkSim, which inherits from networkx and SimPy, to simulate an agent-based model of how messages propagate within networks.
Here is my code:
from ComplexNetworkSim import NetworkSimulation, NetworkAgent, Sim
import networkx as nx
#define constants for our example of states
NO_MESSAGE = 0
MESSAGE = 1
class Message(object):
def __init__(self,topic_pref):
self.relevance = topic_pref
class myAgent(NetworkAgent):
def __init__(self, state, initialiser):
NetworkAgent.__init__(self, state, initialiser)
self.state = MESSAGE
self.topic_pref = 0.5
def Run(self):
while True:
if self.state == MESSAGE:
self.message = self.Message(topic_pref, self, TIMESTEP)
yield Sim.hold, self, NetworkAgent.TIMESTEP_DEFAULT
elif self.state == NO_MESSAGE:
yield Sim.hold, self, NetworkAgent.TIMESTEP_DEFAULT
# Network and initial states of agents
nodes = 30
G = nx.scale_free_graph(nodes)
states = [MESSAGE for n in G.nodes()]
# Simulation constants
MAX_SIMULATION_TIME = 25.0
TRIALS = 2
def main():
directory = 'test' #output directory
# run simulation with parameters
# - complex network structure
# - initial state list
# - agent behaviour class
# - output directory
# - maximum simulation time
# - number of trials
simulation = NetworkSimulation(G,
states,
myAgent,
directory,
MAX_SIMULATION_TIME,
TRIALS)
simulation.runSimulation()
if __name__ == '__main__':
main()
(There may be other problems downstream with this code and it is not fully tested.)
My problem is that the myAgent object is not properly calling the method Run as an attribute. Specifically, this is the error message that I get when I try to run the above code:
Starting simulations...
---Trial 0 ---
set up agents...
Traceback (most recent call last):
File "simmessage.py", line 55, in <module>
main()
File "simmessage.py", line 52, in main
simulation.runSimulation()
File "/Library/Frameworks/EPD64.framework/Versions/7.3/lib/python2.7/site-packages/ComplexNetworkSim-0.1.2-py2.7.egg/ComplexNetworkSim/simulation.py", line 71, in runSimulation
self.runTrial(i)
File "/Library/Frameworks/EPD64.framework/Versions/7.3/lib/python2.7/site-packages/ComplexNetworkSim-0.1.2-py2.7.egg/ComplexNetworkSim/simulation.py", line 88, in runTrial
self.activate(agent, agent.Run())
AttributeError: 'myAgent' object has no attribute 'Run'
Does anybody know why this is? I can't figure how my code differs substantially from the example in ComplexNetworkSim.
I've run your code on my machine and there the Run method gets called.
My best guess is what Paulo Scardine wrote, but since i can't reproduce the problem i can't actually debug it.