Error on Python serial import - python

When I try to import the serial I get the following error:
Traceback (most recent call last):
File "C:\Documents and Settings\eduardo.pereira\workspace\thgspeak\tst.py", line 7, in <module>
import serial
File "C:\Python27\lib\site-packages\serial\__init__.py", line 27, in <module>
from serial.serialwin32 import Serial
File "C:\Python27\lib\site-packages\serial\serialwin32.py", line 15, in <module>
from serial import win32
File "C:\Python27\lib\site-packages\serial\win32.py", line 182, in <module>
CancelIoEx = _stdcall_libraries['kernel32'].CancelIoEx
File "C:\Python27\lib\ctypes\__init__.py", line 375, in __getattr__
func = self.__getitem__(name)
File "C:\Python27\lib\ctypes\__init__.py", line 380, in __getitem__
func = self._FuncPtr((name_or_ordinal, self))
AttributeError: function 'CancelIoEx' not found
I have installed the latest version of pySerial, Python 2.7 runing on a WinXP laptop. Tried everywhere and found no similar problem. Is there any solution for that?
Thanks in advance...

The version of pySerial that you're using is trying to call a function that's only available in Windows Vista, whereas you're running Windows XP.
It might be worth experimenting with using an older version of pySerial.
The code in question was added to pySerial on 3 May 2016, so a version just prior to that might be a good start.

Older versions seem unavailable. But, this worked for me (assuming nanpy version 3.1.1):
open file \lib\site-packages\serial\serialwin32.py
delete methods _cancel_overlapped_io(), cancel_read(), cancel_write() in lines 436-455 nearly at the botton of the file
change method _close() als follows:
(Python)
def _close(self):
"""internal close port helper"""
if self._port_handle is not None:
# Restore original timeout values:
win32.SetCommTimeouts(self._port_handle, self._orgTimeouts)
# Close COM-Port:
if self._overlapped_read is not None:
win32.CloseHandle(self._overlapped_read.hEvent)
self._overlapped_read = None
if self._overlapped_write is not None:
win32.CloseHandle(self._overlapped_write.hEvent)
self._overlapped_write = None
win32.CloseHandle(self._port_handle)
self._port_handle = None
Additionally, create a non-default serial connection when starting the communication, otherwise you'll be bound to some linux device:
a = ArduinoApi(SerialManager("COM5:"))
for i in range(10):
a.pinMode(13, a.OUTPUT)
a.digitalWrite(13, a.HIGH)
# etc.

And in serial\win32.py comments
#CancelIoEx = _stdcall_libraries['kernel32'].CancelIoEx
#CancelIoEx.restype = BOOL
#CancelIoEx.argtypes = [HANDLE, LPOVERLAPPED]

There is no obvious reason why CancelIO was replaced with the cross-thread version CancelIOex, which allows code in one thread to cancel IO in another thread. Certainly cpython 2.x is single threaded.
To get pySerial to run on python 2.7 on Win2K, I just changed CancelIOex in serial back to CancelIO.

Related

Can't initialize ANT+ Node with Python OpenANT library

I've totally new in Python and also in the ANT+ technology. I wonder if that's not some basic problem, but I've been strugling with it for couple of days already browsing through forums with no luck..
So I'm trying to use the Python OpenANT library (https://github.com/Tigge/openant) to access my ANT doungle which is plugged into the USB port (WINDOWS 10 PRO). My goal is to access my Garmin through it and get some data from it. However, I'm stuck at the very beginning trying to inizialize the ANT Node. My code is this:
from ant.easy.node import Node
node=Node()
To this I get the exception:
File "C:/Users/Edgars/Desktop/untitled-5.py", line 2, in <module>
pass
File "C:\Users\Edgars\AppData\Local\Programs\Python\Python38-32\Lib\site-packages\ant\easy\node.py", line 56, in __init__
self.ant = Ant()
File "C:\Users\Edgars\AppData\Local\Programs\Python\Python38-32\Lib\site-packages\ant\base\ant.py", line 68, in __init__
self._driver.open()
File "C:\Users\Edgars\AppData\Local\Programs\Python\Python38-32\Lib\site-packages\ant\base\driver.py", line 193, in open
cfg = dev.get_active_configuration()
File "C:\Users\Edgars\AppData\Local\Programs\Python\Python38-32\lib\site-packages\pyusb-1.1.0-py3.8.egg\usb\core.py", line 909, in get_active_configuration
return self._ctx.get_active_configuration(self)
File "C:\Users\Edgars\AppData\Local\Programs\Python\Python38-32\lib\site-packages\pyusb-1.1.0-py3.8.egg\usb\core.py", line 113, in wrapper
return f(self, *args, **kwargs)
File "C:\Users\Edgars\AppData\Local\Programs\Python\Python38-32\lib\site-packages\pyusb-1.1.0-py3.8.egg\usb\core.py", line 250, in get_active_configuration
bConfigurationValue=self.backend.get_configuration(self.handle)
File "C:\Users\Edgars\AppData\Local\Programs\Python\Python38-32\lib\site-packages\pyusb-1.1.0-py3.8.egg\usb\backend\libusb0.py", line 519, in get_configuration
ret = self.ctrl_transfer(
File "C:\Users\Edgars\AppData\Local\Programs\Python\Python38-32\lib\site-packages\pyusb-1.1.0-py3.8.egg\usb\backend\libusb0.py", line 601, in ctrl_transfer
return _check(_lib.usb_control_msg(
File "C:\Users\Edgars\AppData\Local\Programs\Python\Python38-32\lib\site-packages\pyusb-1.1.0-py3.8.egg\usb\backend\libusb0.py", line 447, in _check
raise USBError(errmsg, ret)
usb.core.USBError: [Errno None] b'libusb0-dll:err [control_msg] sending control message failed, win error: A device which does not exist was specified.\r\n\n'
I have closed the Garmin Agent, so no other programs are using my ANT dongle at the same time. When I run my code, the specific sound occurs every time - the one that we hear when we detach a USB device by selecting "Eject" from the drop-down menu (the sound happens simultaneously with the exception message), so I guess the USB gets accessed at some moment.
Before the exception I get such a printout:
Driver available: [<class 'ant.base.driver.SerialDriver'>, <class 'ant.base.driver.USB2Driver'>, <class 'ant.base.driver.USB3Driver'>]
- Using: <class 'ant.base.driver.USB3Driver'>
Could not check if kernel driver was active, not implemented in usb backend
I have seen other users' threads where the printout says Using ... USB1Driver or Using ... USB2Driver, and they don't get this message. I've installed various python libraries trying to get even this far, and now I've worried that maybe they get in each other's way.. Can anybody help me with this? It's really frustrating that a program of only two code lines can get so complicated.. :D
!!!EDIT!!!
OK, I found the problem - in the "driver.py" file there's a line dev.reset() which disconnects my USB dongle before trying to access it. I have no idea why such a line should exist there. I tried to comment this line out, and now I'm not getting the abovementioned error anymore. However, what happens now is there are continuos timeouts..
So my code has evolved to this (although actually the same timeouts happen also with my initial 2-lines-long program):
from ant.easy.node import Node
from ant.easy.channel import Channel
from ant.base.message import Message
import threading
NETWORK_KEY=[0xb9,0xa5,0x21,0xfb,0xbd,0x72,0xc3,0x45]
def on_data(data):
print("Data received")
print(data)
def back_thread(node):
node.set_network_key(0x00,NETWORK_KEY)
channel=node.new_channel(Channel.Type.BIDIRECTIONAL_RECEIVE)
channel.on_broadcast_data=on_data
channel.on_burst_data=on_data
channel.set_period(16070)
channel.set_search_timeout(20)
channel.set_rf_freq(57)
channel.set_id(0,120,0)
try:
channel.open()
node.start()
finally:
node.stop()
print("ANT Node Shutdown Complete")
node=Node()
x=threading.Thread(target=back_thread,args=(node,))
x.start()
Now I get this error line printed out for ever:
<class 'usb.core.USBError'>, (None, b'libusb0-dll:err [_usb_reap_async] timeout error\n')
When my Garmin Agent is active, I get the error "ANT resource already in use" instead of the timeout, so I'm certain that my code is accessing the ANT dongle.. However, now (having closed the Garmin Agent) I have no idea about how to get rid of the timeout and how to establish a simple handshake with my Garmin device..
OK, now I've figured out that my Garmin Forerunner 310XT can't act as a data source and thus cannot be accessed using the ANT+ protokol. Instead, I should use the ANT-FS protocol of File Sharing. Keeping my head down and trying it out...
I posted a PR with some changes that I made to get Tigge’s openant library to work. Basically, I put a pause after the reset line that you mentioned above and bypassed the use of udev_rules as it doesn’t apply in Windows. You can use libusb but installation is a bit different. I’ve added Windows installation instructions to the readme in the PR with details on what worked for me.

Python can't import WMI under special circumstance

I've created a standalone exe Windows service written in Python and built with pyInstaller. When I try to import wmi, an exception is thrown.
What's really baffling is that I can do it without a problem if running the code in a foreground exe, or a foreground python script, or a python script running as a background service via pythonservice.exe!
Why does it fail under this special circumstance of running as a service exe?
import wmi
Produces this error for me:
com_error: (-2147221020, 'Invalid syntax', None, None)
Here's the traceback:
Traceback (most recent call last):
File "<string>", line 43, in onRequest
File "C:\XXX\XXX\XXX.pyz", line 98, in XXX
File "C:\XXX\XXX\XXX.pyz", line 31, in XXX
File "C:\XXX\XXX\XXX.pyz", line 24, in XXX
File "C:\XXX\XXX\XXX.pyz", line 34, in XXX
File "C:\Program Files (x86)\PyInstaller-2.1\PyInstaller\loader\pyi_importers.py", line 270, in load_module
File "C:\XXX\XXX\out00-PYZ.pyz\wmi", line 157, in <module>
File "C:\XXX\XXX\out00-PYZ.pyz\win32com.client", line 72, in GetObject
File "C:\XXX\XXX\out00-PYZ.pyz\win32com.client", line 87, in Moniker
wmi.py line 157 has a global call to GetObject:
obj = GetObject ("winmgmts:")
win32com\client__init.py__ contains GetObject(), which ends up calling Moniker():
def GetObject(Pathname = None, Class = None, clsctx = None):
"""
Mimic VB's GetObject() function.
ob = GetObject(Class = "ProgID") or GetObject(Class = clsid) will
connect to an already running instance of the COM object.
ob = GetObject(r"c:\blah\blah\foo.xls") (aka the COM moniker syntax)
will return a ready to use Python wrapping of the required COM object.
Note: You must specifiy one or the other of these arguments. I know
this isn't pretty, but it is what VB does. Blech. If you don't
I'll throw ValueError at you. :)
This will most likely throw pythoncom.com_error if anything fails.
"""
if clsctx is None:
clsctx = pythoncom.CLSCTX_ALL
if (Pathname is None and Class is None) or \
(Pathname is not None and Class is not None):
raise ValueError("You must specify a value for Pathname or Class, but not both.")
if Class is not None:
return GetActiveObject(Class, clsctx)
else:
return Moniker(Pathname, clsctx)
The first line in Moniker(), i.e. MkParseDisplayName() is where the exception is encountered:
def Moniker(Pathname, clsctx = pythoncom.CLSCTX_ALL):
"""
Python friendly version of GetObject's moniker functionality.
"""
moniker, i, bindCtx = pythoncom.MkParseDisplayName(Pathname)
dispatch = moniker.BindToObject(bindCtx, None, pythoncom.IID_IDispatch)
return __WrapDispatch(dispatch, Pathname, clsctx=clsctx)
Note: I tried using
pythoncom.CoInitialize()
which apparently solves this import problem within a thread, but that didn't work...
I also face the same issue and I figure out this issue finally,
import pythoncom and CoInitialize pythoncom.CoInitialize (). They import wmi
import pythoncom
pythoncom.CoInitialize ()
import wmi
I tried solving this countless ways. In the end, I threw in the towel and had to just find a different means of achieving the same goals I had with wmi.
Apparently that invalid syntax error is thrown when trying to create an object with an invalid "moniker name", which can simply mean the service, application, etc. doesn't exist on the system. Under this circumstance "winmgmts" just can't be found at all it seems! And yes, I tried numerous variations on that moniker with additional specs, and I tried running the service under a different user account, etc.
Honestly I didn't dig in order to understand why this occurs.
Anyway, the below imports solved my problem - which was occurring only when ran from a Flask instance:
import os
import pythoncom
pythoncom.CoInitialize()
from win32com.client import GetObject
import wmi
The error "com_error: (-2147221020, 'Invalid syntax', None, None)" is exactly what popped up in my case so I came here after a long time of searching the web and voila:
Under this circumstance "winmgmts" just can't be found at all it
seems!
This was the correct hint for because i had just a typo , used "winmgmt:" without trailing 's'. So invalid sythax refers to the first methods parameter, not the python code itself. o_0 Unfortunately I can't find any reference which objects we can get with win32com.client.GetObject()... So if anybody has a hint to which params are "allowed" / should work, please port it here. :-)
kind regards
ChrisPHL

uTorrent Automation using pywinauto

I am trying out an utorrent automation using pywinauto lib. I want to add a torrent with URL. This option is under the file menu. I can get as far as opening uTorrent and then nothing happens. I used Swapy for generating this code. The box below opens only when I run the code in swapy. But when I save it into a file and run with cmd, only utorrent opens and a traceback occurs in the cmd.
from pywinauto.application import Application
app = Application().Start(cmd_line=u'"C:\\Users\\User\\AppData\\Roaming\\uTorrent\\u Torrent.exe" ')
torrentdfb = app[u'\xb5Torrent4823DF041B09']
torrentdfb.Wait('ready')
menu_item = torrentdfb.MenuItem(u'&File->Add Torrent from &URL...\tCtrl+U')
menu_item.Click()
app.Kill_()
Traceback:
Traceback (most recent call last):
File "AddTorrent.py", line 5, in <module>
torrentdfb.Wait('ready')
File "C:\Python27\lib\site-packages\pywinauto\application.py", line 380, in Wait
WaitUntil(timeout, retry_interval, lambda: self.__check_all_conditions(check_method_names))
File "C:\Python27\lib\site-packages\pywinauto\timings.py", line 308, in WaitUntil
raise err
pywinauto.timings.TimeoutError: timed out
I am new to python coding and I am not an expert. It would be helpful if you provide the explanation to solve my problem or the code. Thanks!!
uTorrent is spawning another process, this is how I got it:
>>> app.windows_()
[]
>>> app.process
6096
>>> app.connect(title_re=u'^μTorrent.*(build \d+).*')
<pywinauto.application.Application object at 0x000000000405C240>
>>> app.process
4044L
This is a final code working for me (with 32-bit uTorrent and 32-bit Python 2.7):
import pywinauto
app = pywinauto.Application().start(r'uTorrent.exe')
time.sleep(5) # because method connect() has no timeout param yet (planned for 0.6.0)
app.connect(title_re=u'^\u03bcTorrent.*(build \d+).*')
main_window = app.window_(title_re=u'^\u03bcTorrent.*(build \d+).*')
main_window.MenuSelect(u'&File->Add Torrent from &URL...\tCtrl+U')
app.AddTorrentFromURL.Edit.SetText('some URL')
app.AddTorrentFromURL.OK.Click()
Bitness is important. 32-bit uTorrent crashes if I use 64-bit Python.

winpdb not working with python 3.3

I can't get rpdb2 to run with python 3.3, while that should be possible according to several sources.
$ rpdb2 -d myscript.py
A password should be set to secure debugger client-server communication.
Please type a password:x
Password has been set.
Traceback (most recent call last):
File "/usr/local/bin/rpdb2", line 31, in <module>
rpdb2.main()
File "/usr/local/lib/python3.3/dist-packages/rpdb2.py", line 14470, in main
StartServer(_rpdb2_args, fchdir, _rpdb2_pwd, fAllowUnencrypted, fAllowRemote, secret)
File "/usr/local/lib/python3.3/dist-packages/rpdb2.py", line 14212, in StartServer
g_module_main = -1
File "/usr/local/lib/python3.3/dist-packages/rpdb2.py", line 14212, in StartServer
g_module_main = -1
File "/usr/local/lib/python3.3/dist-packages/rpdb2.py", line 7324, in trace_dispatch_init
self.__set_signal_handler()
File "/usr/local/lib/python3.3/dist-packages/rpdb2.py", line 7286, in __set_signal_handler
handler = signal.getsignal(value)
File "/usr/local/lib/python3.3/dist-packages/rpdb2.py", line 13682, in __getsignal
handler = g_signal_handlers.get(signum, g_signal_getsignal(signum))
ValueError: signal number out of range
The version of rpdb2 is RPDB 2.4.8 - Tychod.
I installed it by running pip-3.3 install winpdb.
Any clues?
Got the same problem today here is what i've done for it to work.
Still i'm not too sure if this is correct to do it this way.
From:
def __getsignal(signum):
handler = g_signal_handlers.get(signum, g_signal_getsignal(signum))
return handler
To:
def __getsignal(signum):
try:
# The problems come from the signum which was 0.
g_signal_getsignal(signum)
except ValueError:
return None
handler = g_signal_handlers.get(signum, g_signal_getsignal(signum))
return handler
This function shall be at line 13681 or something like.
The reason of a problem is the extended list of attributes in a signal module that was used by rpdb2 to list all signals. New python versions added attributes like SIG_BLOCK, SIG_UNBLOCK, SIG_SETMASK
So the filtering should be extended too (patch changes just one line):
--- rpdb2.py
+++ rpdb2.py
## -7278,11 +7278,11 ##
def __set_signal_handler(self):
"""
Set rpdb2 to wrap all signal handlers.
"""
for key, value in list(vars(signal).items()):
- if not key.startswith('SIG') or key in ['SIGRTMIN', 'SIGRTMAX'] or key.startswith('SIG_'):
+ if not key.startswith('SIG') or key in ['SIG_IGN', 'SIG_DFL', 'SIGRTMIN', 'SIGRTMAX']:
continue
handler = signal.getsignal(value)
if handler in [signal.SIG_IGN, signal.SIG_DFL]:
continue
Unfortunately there is no current official development or fork of winpdb, so by now this patch would be just stored on SO.

Something wrong with ViewClient.connectToDeviceOrExit()

I'm recently started to use python with mobile app automation, as i decided to use python, the main instruments that I've found were monkeyrunner and androidviewclient.
But there is the first issue with which i dont know what to do:
package = 'com.mypackage.android'
activity = '.launchActivity'
component = package + "/" + activity
device, serialno = ViewClient.connectToDeviceOrExit()
device.startActivity(component=component)
time.sleep(3)
vc = ViewClient(device, serialno)
vc.dump()
showMenu = vc.findViewById("id/no_id/8")
showMenu.touch()
as i'm running it in windows cmd - monkeyrunner mypath\test-case1.py
i receive an exception:
131213 18:42:32.555:S [MainThread] [com.android.monkeyrunner.MonkeyRunnerOptions] Script terminated due to an exception
131213 18:42:32.555:S [MainThread] [com.android.monkeyrunner.MonkeyRunnerOptions]Traceback (most recent call last):
File "C:\Python27\tests\1.py", line 26, in <module>
device, serialno = ViewClient.connectToDeviceOrExit()
File "C:\Program Files (x86)\Android\AndroidViewClient\AndroidViewClient-maste
r\AndroidViewClient\src\com\dtmilano\android\viewclient.py", line 1381, in conne
ctToDeviceOrExit
ViewClient.setAlarm(timeout+5)
File "C:\Program Files (x86)\Android\AndroidViewClient\AndroidViewClient-maste
r\AndroidViewClient\src\com\dtmilano\android\viewclient.py", line 1341, in setAl
arm
signal.alarm(timeout)
File "C:\Program Files (x86)\Android\android-sdk\tools\lib\jython-standalone-2
.5.3.jar\Lib\signal.py", line 222, in alarm
NotImplementedError: alarm not implemented on this platform
am I doing something wrong? Please help.
Thank you a lot!
This is how setAlarm looks like
#staticmethod
def setAlarm(timeout):
osName = platform.system()
if osName.startswith('Windows'): # alarm is not implemented in Windows
return
signal.alarm(timeout)
so, it tries to identify that is Windows and then not invoking signal.alarm() which is not implemented, but for some reason it fails in your case.
Try to print the result of osName to see what went wrong.
UPDATE
Now I see, you are using monkeyrunner as the interpreter but AndroidViewClient >= 4.0.0 is 100% pure python, so you should run your scripts using a python 2.x interpreter.

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