🌐 Mailman 3 November 2018 - Python-list - python.org

Re: ConfigParser: use newline in INI file
by Ned Batchelder March 7, 2019

March 7, 2019

On Saturday, October 1, 2016 at 6:25:16 PM UTC-4, Thorsten Kampe wrote: > * Ben Finney (Sun, 02 Oct 2016 07:12:46 +1100) > > > > Thorsten Kampe <thorsten(a)thorstenkampe.de> writes: > > > > > ConfigParser escapes `\n` in ini values as `\\n`. > > Indenting solves the problem. I'd rather keep it one line per value > but it solves the problem. If you want to have \n mean a newline in your config file, you can do the conversion after you read the value: >>> "a\\nb".decode("string-escape") 'a\nb' --Ned.

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Encounter issues to install Python
by Olivier Oussou Jan. 15, 2019

Jan. 15, 2019

Hi!I downloaded and installed python 3.6.4 (32-bit) on my computer but I have problems and can not access the python interface. I need your technical assistance to solve this matter. Best regard! Olivier OUSSOUMedical entomologist, Benin

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Python Interview Questions
by Krypto Jan. 10, 2019

Jan. 10, 2019

Hi, I have used Python for a couple of projects last year and I found it extremely useful. I could write two middle size projects in 2-3 months (part time). Right now I am a bit rusty and trying to catch up again with Python. I am now appearing for Job Interviews these days and I am wondering if anybody of you appeared for a Python Interview. Can you please share the questions you were asked. That will be great help to me. Thanks,

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How to use multiple instances of the same COM object at the same time
by Jan Dec. 18, 2018

Dec. 18, 2018

Dear Usenet readers, Our company wants to implement about 40 biometric access control devices which have a proprietary DLL with a COM object in it. I've done some research about COM objects and how to use them. Now, I need to connect to every device separately and register for real time events. So, I need about 40 instances of the COM object simultaneously connected and registered to catch all events of all devices. I assumed I needed threading for this, and I have done a simple implementation. All I want to ask is: Does anybody see something that I could have done in a better way? I'm new to COM objects in Python! The program runs fine, it is very basic and I tested it with 3 devices connected at the same time. In production this will be 40! Thanks in advance Jan Source code: # Based on eventappartmentthreading from the win32com demo import sys, os, time import win32com.client import win32api import win32event # sys.coinit_flags not set, so pythoncom initializes apartment-threaded. import pythoncom from threading import Thread threadlist = dict() # this stores the device ids # using the threadid as the key field class ZkEvents: def __init__(self): self.event = win32event.CreateEvent(None, 0, 0, None) thread = win32api.GetCurrentThreadId() print "thread %s " % thread self.dev_id = threadlist[thread] print "Thread Connected For ID %s " % self.dev_id def OnFinger(self): print self.dev_id, print "OnFinger" def OnVerify(self, iUserID=pythoncom.Empty): print self.dev_id, print "OnVerify: %s" % iUserID def OnKeyPress(self, iKey=pythoncom.Empty): print self.dev_id, print "KeyPress: %s" % iKey def WaitWhileProcessingMessages(event, timeout = 60): start = time.clock() while True: # Wake 4 times a second - we can't just specify the # full timeout here, as then it would reset for every # message we process. rc = win32event.MsgWaitForMultipleObjects( (event,), 0, 250, win32event.QS_ALLEVENTS) if rc == win32event.WAIT_OBJECT_0: # event signalled - stop now! return True if (time.clock() - start) > timeout: # Timeout expired. return False # must be a message. pythoncom.PumpWaitingMessages() def TestZkEvents(ip, dev_id): thread = win32api.GetCurrentThreadId() print 'TestZkEvents created ZK object on thread %d'%thread threadlist[thread] = dev_id pythoncom.CoInitialize() zk = win32com.client.DispatchWithEvents("zkemkeeper.ZKEM", ZkEvents) if zk.Connect_Net(ip, 4370): print "Connect %s OK" % ip else: print "Connect %s Failed" % ip try: if zk.RegEvent(1, 65535): # 65535 = register for all events print "RegEvent %s, %s OK" % (ip, dev_id) else: print "RegEvent %s, %s Failed" % (ip, dev_id) except pythoncom.com_error, details: print "Warning - could not open the test HTML file", details # Wait for the event to be signaled while pumping messages. while True: if not WaitWhileProcessingMessages(zk.event): print "No Events From %s During Last Minute" % dev_id zk = None if __name__=='__main__': # this should be a for loop with database fields... t1 = Thread(target=TestZkEvents, args=('192.168.1.211',40)) t1.start() t2 = Thread(target=TestZkEvents, args=('192.168.1.212',45)) t2.start() t3 = Thread(target=TestZkEvents, args=('192.168.1.213',49)) t3.start()

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ipython does not work with latest version of prompt-toolkit
by Cecil Westerhof Dec. 18, 2018

Dec. 18, 2018

When executing: pip3 list --no-cache-dir --outdated I got: prompt-toolkit 1.0.15 2.0.1 wheel PyGObject 3.28.2 3.28.3 sdist youtube-dl 2018.5.30 2018.6.2 wheel So I executed: pip3 install --upgrade prompt-toolkit PyGObject youtube-dl This gave: Successfully installed PyGObject-3.28.3 prompt-toolkit-2.0.1 youtube-dl-2018.6.2 ipython 6.4.0 has requirement prompt-toolkit<2.0.0,>=1.0.15, but you'll have prompt-toolkit 2.0.1 which is incompatible. And when I now execute ipython3, I get: Traceback (most recent call last): File "/usr/local/bin/ipython3", line 7, in <module> from IPython import start_ipython File "/usr/local/lib/python3.5/dist-packages/IPython/__init__.py", line 55, in <module> from .terminal.embed import embed File "/usr/local/lib/python3.5/dist-packages/IPython/terminal/embed.py", line 16, in <module> from IPython.terminal.interactiveshell import TerminalInteractiveShell File "/usr/local/lib/python3.5/dist-packages/IPython/terminal/interactiveshell.py", line 22, in <module> from prompt_toolkit.shortcuts import create_prompt_application, create_eventloop, create_prompt_layout, create_output ImportError: cannot import name 'create_prompt_application' When I now execute: pip3 list --no-cache-dir --outdated I do not get output. So pip3 thinks everything is OK. How do I fix this? Or is the expected that ipython3 will be updated shortly? -- Cecil Westerhof Senior Software Engineer LinkedIn: http://www.linkedin.com/in/cecilwesterhof

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python CAD libraries?
by Jayden Dec. 13, 2018

Dec. 13, 2018

Are there any python CAD libraries that can (1) build simple 3D primitives solids such as spheres, cylinders and so on (2) perform bool operations on 3D solids (3) better if it has some transformations such has scaling, sweeping, and lofting Please recommend some good ones for me? Thanks a lot!!

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ValueError vs IndexError, unpacking arguments with string.split
by Morten W. Petersen Dec. 2, 2018

Dec. 2, 2018

Hi there. I was adding a port specification feature to my surveil project as shown here: https://github.com/morphex/surveil/commit/703318f87c4c450a37944b565a10718ef… A bit later I was surprised when the script raised an exception, and that I had to catch a ValueError instead of an IndexError: https://github.com/morphex/surveil/commit/d5c49c54d4037557aaca1f78178b76441… I've been reading up on a bit of C++, Assembler etc. lately, so maybe my mind expected an IndexError because of that, but isn't it logical that the string is parsed and split, and then later the unpacking operation fails with an IndexError? Regards, Morten -- Videos at https://www.youtube.com/user/TheBlogologue Twittering at http://twitter.com/blogologue Blogging at http://blogologue.com Playing music at https://soundcloud.com/morten-w-petersen Also playing music and podcasting here: http://www.mixcloud.com/morten-w-petersen/ On Google+ here https://plus.google.com/107781930037068750156 On Instagram at https://instagram.com/morphexx/

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Re: multiple JSON documents in one file, change proposal
by Marko Rauhamaa Dec. 2, 2018

Dec. 2, 2018

Paul Rubin <no.email(a)nospam.invalid>: > Maybe someone can convince me I'm misusing JSON but I often want to > write out a file containing multiple records, and it's convenient to > use JSON to represent the record data. > > The obvious way to read a JSON doc from a file is with "json.load(f)" > where f is a file handle. Unfortunately, this throws an exception I have this "multi-JSON" need quite often. In particular, I exchange JSON-encoded messages over byte stream connections. There are many ways of doing it. Having rejected different options (<URL: https://en.wikipedia.org/wiki/JSON_streaming>), I settled with terminating each JSON value with an ASCII NUL character, which is illegal in JSON proper. > I also recommend the following article to those not aware of how badly > designed JSON is: http://seriot.ch/parsing_json.php JSON is not ideal, but compared with XML, it's a godsend. What would be ideal? I think S-expressions would come close, but people can mess up even them: <URL: https://www.ietf.org/rfc/rfc2693.txt>. Marko

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Re: RAR functionality
by Wildman Nov. 30, 2018

Nov. 30, 2018

On Fri, 30 Nov 2018 16:42:06 -0500, Benjamin Schollnick wrote: > Folks, > > Can anyone explain to me why RAR support isn’t available natively in python? > > We have the zipfile and tarfile modules… > > Yes, there is rarfile and PaTools but they both rely on RAR being available to shell out to… > What is it about RAR files that makes it unreasonable to handle in natively in python? > Licensing? Bad rar file design? > > - Benjamin RAR is proprietary. -- <Wildman> GNU/Linux user #557453 The cow died so I don't need your bull!

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Error Python version 3.6 does not support this syntax.
by srinivasan Nov. 29, 2018

Nov. 29, 2018

Dear Python Experts, As still I am newbie and learning python, I am trying to reuse the Bluetoothctl wrapper in Python from the link ( https://gist.github.com/egorf/66d88056a9d703928f93) I am using python3.6 version, In pycharm editor on the bold highlighted code snippets I see the error message "Python version 3.6 does not support this syntax.", Could you please how help me how the below highlighted lines of code can be can be ported to python3.6 version? * except BluetoothctlError, e:* * print(e)* * return None* Full Code snippet: ============== import time import pexpect import subprocess import sys class BluetoothctlError(Exception): """This exception is raised, when bluetoothctl fails to start.""" pass class Bluetoothctl: """A wrapper for bluetoothctl utility.""" def __init__(self): out = subprocess.check_output("rfkill unblock bluetooth", shell = True) self.child = pexpect.spawn("bluetoothctl", echo = False) def get_output(self, command, pause = 0): """Run a command in bluetoothctl prompt, return output as a list of lines.""" self.child.send(command + "\n") time.sleep(pause) start_failed = self.child.expect(["bluetooth", pexpect.EOF]) if start_failed: raise BluetoothctlError("Bluetoothctl failed after running " + command) return self.child.before.split("\r\n") def start_scan(self): """Start bluetooth scanning process.""" try: out = self.get_output("scan on") * except BluetoothctlError, e: print(e) return None* def make_discoverable(self): """Make device discoverable.""" try: out = self.get_output("discoverable on") * except BluetoothctlError, e: print(e) return None* def parse_device_info(self, info_string): """Parse a string corresponding to a device.""" device = {} block_list = ["[\x1b[0;", "removed"] string_valid = not any(keyword in info_string for keyword in block_list) if string_valid: try: device_position = info_string.index("Device") except ValueError: pass else: if device_position > -1: attribute_list = info_string[device_position:].split(" ", 2) device = { "mac_address": attribute_list[1], "name": attribute_list[2] } return device def get_available_devices(self): """Return a list of tuples of paired and discoverable devices.""" try: out = self.get_output("devices") * except BluetoothctlError, e: print(e) return None* else: available_devices = [] for line in out: device = self.parse_device_info(line) if device: available_devices.append(device) return available_devices def get_paired_devices(self): """Return a list of tuples of paired devices.""" try: out = self.get_output("paired-devices") * except BluetoothctlError, e: print(e) return None* else: paired_devices = [] for line in out: device = self.parse_device_info(line) if device: paired_devices.append(device) return paired_devices def get_discoverable_devices(self): """Filter paired devices out of available.""" available = self.get_available_devices() paired = self.get_paired_devices() return [d for d in available if d not in paired] def get_device_info(self, mac_address): """Get device info by mac address.""" try: out = self.get_output("info " + mac_address) * except BluetoothctlError, e: print(e) return None* else: return out def pair(self, mac_address): """Try to pair with a device by mac address.""" try: out = self.get_output("pair " + mac_address, 4) * except BluetoothctlError, e: print(e) return None* else: res = self.child.expect(["Failed to pair", "Pairing successful", pexpect.EOF]) success = True if res == 1 else False return success def remove(self, mac_address): """Remove paired device by mac address, return success of the operation.""" try: out = self.get_output("remove " + mac_address, 3) * except BluetoothctlError, e: print(e) return None* else: res = self.child.expect(["not available", "Device has been removed", pexpect.EOF]) success = True if res == 1 else False return success def connect(self, mac_address): """Try to connect to a device by mac address.""" try: out = self.get_output("connect " + mac_address, 2) * except BluetoothctlError, e: print(e) return None* else: res = self.child.expect(["Failed to connect", "Connection successful", pexpect.EOF]) success = True if res == 1 else False return success def disconnect(self, mac_address): """Try to disconnect to a device by mac address.""" try: out = self.get_output("disconnect " + mac_address, 2) * except BluetoothctlError, e: print(e) return None* else: res = self.child.expect(["Failed to disconnect", "Successful disconnected", pexpect.EOF]) success = True if res == 1 else False return success kindly do the needful, Many Thanks in advance,

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