I'm working on a program that needs some threading. I wanted to get myself into this and tried several tutorials. Because of some special hardware I need to stick to Python 2.5.2 (r25:51908)
When I want to run the following code
import threading
class PrintThread(threading.Thread):
def run(self):
print "foobar"
thread = PrintThread()
thread.start()
I get the famous error "pythonw.exe has encountered a problem ...". This only happens on my PC. When I tried the very same code on a differenct PC with the same installation of Python (also with the same additional libraries like visa), it just works!
I uninstalled Python and reinstalled it again, but the error is still occuring. Any suggestions?
Related
I was using Raspberry Pi to perform some basic experiments and I wrote some Python scripts for that and they were fine. Then, for a new part of the analysis, I had to import SciPy. To be able to use SciPy, I had to install an older version. After that, I'm getting "ImportError" for every module. For example:
ImportError: cannot import name 'process' from partially initialized module 'multiprocessing' (most likely due to a circular import)"
Some people said it might be because of having the same script filename which will conflict with the multiprocessing module but this is not true in my case.
Also, I tried the analysis part of the code on different systems (Ubuntu on my laptop) and it works fine so I'm sure there is nothing wrong with the code.
I'm wondering if anyone else has ever had the same issue on Raspberry Pi?
Best regards,
Amir
So I am trying to write some python code that will do two things, that seem to be mutually exclusive on my machine. My PC's host operating system is windows and I run Kali-Linux in WSL2 when I need to test my code on Linux. My code's main function creates two separate multiprocessing.Process objects, assigning a different thread, starting them both one after the other and then calling for them both to be joined. The plan is to allow each to run a simple server application simultaneously on different ports. This does not work when running python3 in PowerShell, as it seems to require access to os.fork() which doesn't work in said environment. When I found this out I pivoted to running in WSL2 which worked fantastically, for a time. After a while of experimenting with some ideas I decided to take some of my code and spin it off into its own file, which I placed in its own 'Libs' folder. WSL2 however, was unable to import this new file, instead giving me the exception ModuleNotFoundError: No module named 'NetStuff'. I originally had added:
sys.path.append('./Libs')
as has worked for me in the past, however when I found that WSL2 was unable to find my module, I printed out sys.path and it revealed that rather than appending my $current_working_directory/Libs like I intended, I was just appending the literal string, which wasn't useful. I then decided to try:
sys.path.append(str(pathlib.Path().resolve()) + '/Libs')
which at the bare minimum shows up as I would expect in sys.path. This, however still didn't work, python was unable to find my module and would unceremoniously crash every time. This led me to try something else, I ran my code in python3 under PowerShell again, which had no issue importing my module, it did still crash due to lacking os.fork() but the import gave no issues. Confused and annoyed I opened my code in IDLE 3.9 which, for some inexplicable reason, was able to import the file, and seemingly use os.fork(). The only major issue with running in IDLE is that it is seemingly incapable of understanding ascii colour escape characters. Given that the goal is to run my code in bash, and ideally also PowerShell, I am not satisfied with this as a solution. I returned to trying to fix the issue in WSL2 by adding my module to /home/Noah/bin, and appending this directory to sys.path, but this has still not so much as given me a new symptom.
I am utterly at a loss at this point. none of the fixes I know off hand are working, and neither are the new ones I've found online. I can't tell if I'm just missing something fundamental about python or if I'm running into a bug, if it's the latter, i can't seem to find other people with the same issue. As a result of my confusion and frustration I am appealing to you, kind users of stackoverflow.
The following is the snippet that is causing me problems in WSL2:
path0 = ('/home/Noah/bin')
path1 = (str(pathlib.Path().resolve()) + '/Libs')
sys.path.append(path0)
sys.path.append(path1)
print(sys.path)
import NetStuff
The following is output of print(sys.path) in WSL2:
['/mnt/c/Users/Noah/VSCodeRepos/Python/BlackPack', '/usr/lib/python39.zip', '/usr/lib/python3.9', '/usr/lib/python3.9/lib-dynload', '/home/noah/.local/lib/python3.9/site-packages', '/usr/local/lib/python3.9/dist-packages', '/usr/lib/python3/dist-packages', '/home/Noah/bin', '/mnt/c/Users/Noah/VSCodeRepos/Python/BlackPack/Libs']
The following is the error being thrown by WSL2:
Traceback (most recent call last):
File "/mnt/c/Users/Noah/VSCodeRepos/Python/BlackPack/BlackPackServer.py", line 21, in <module>
import NetStuff
ModuleNotFoundError: No module named 'NetStuff'
I am specifically hoping to fix the issue with WSL2 at the moment as I am fairly certain that getting the code to run on PowerShell is merely going to require rewriting my code so that it doesn't rely on os.fork(). Thank you for reading my problem, and if I left out any information that you would like to see just tell me and I'll add it in an edit!
Edit: I instantly realized that I should specify that my host machine is running windows 10.
module path lost in multiprocessing spawn (ModuleNotFoundError)
The so-called solution of inserting sys-path above the importing of the module does not work for me.
Here is my main.py
import multiprocessing
from testing import customfunction
customfunction(1,2,3)
if __name__ == "__main__":
process = multiprocessing.Process(target=customfunction)
process.start()
process.join()
print("DONE")
The main.py works fine up to process.start()
This means customfunction has been imported properly
Here is my testing.py
import random
def customfunction(size, test, hello):
random.seed(size)
print(random.random())
return random.random()
Both main.py and testing.py are in the same folder. A separate folder with an init.py file did not work as well.
I get this error:
from testing import customfunction
ModuleNotFoundError: No module named 'testing'
I can not wrap my head around why does the process created not retain the system pathing in order to import the file. If i place the multiprocessing creation in customfunction it doesn't work either, the same error occurs.
The link I shared at the top does not work for me as well.
Thank you for taking the time to read. If you believe this is a duplicate of another question, please link it and explain, I am new to python.
EDIT:
I am using Windows 10 as my OS
I have installed Spyder 4.1.4 using Anaconda Navigator, Python 3.7.7.
I installed using a executable package.
I have tested this code on VS Code as well.
I am running this via the two IDEs mentioned(E.G VS Code Powershell console and Spyder's Python Console by clicking run)
I generally currently believe it is an issue specific to my computer, and I'll like to know if its replicable in other Windows Systems and whether or not the linked "solution" in the first line works. With that I may be able to pinpoint my errors
This should work if you invoke multiprocessing.Process(target=customfunction, args=(1,2,3)) instead. I can't think of a reason why this would not work on Linux.
Can you update your question and provide the following information?
What OS are you using?
What version of Python are you running, and how was it installed?
How are you running main.py (e.g. from the command line, from an IDE, etc.)?
Any other details about your system configuration that might help others answer your question?
No multiprocessing print outputs (Spyder)
The solution mentioned here seems to solve my problem, I never expected either VS Code or Spyder's Console to have an issue with multiprocessing, but running the code in an external system terminal works.
Thank you to Melih Elibol for helping me think more clearly about the problem, I am new to python.
I'm running Python code in VS Code (1.28.2, with the Python, and Python Extension Pack extensions) and am using the 'Run Selection/Line in Python Terminal' (Shift+Enter) functionality to just run selected code in the Python terminal.
This has always worked well, but today I'm getting a new line added between each line of code in the terminal, i.e. if I ran:
import heapq
import pickle
the output in the terminal would be:
>>>import heapq
>>>
>>>import pickle
At first, this just seems like an annoyance, but any for loops or functions now come out with an indentation error...so essentially I can't successfully run any code.
I've tried re-installing VS Code as well as installing an older version of VS Code but all give the same problem.
It's so odd because it was working fine and then all of a sudden it changed. The only thing I can think of that has possibly changed is I installed the JSON Tools extension, but I don't believe this would change anything within Python (and I've tried uninstalling this, and not loading it again when reinstalling VS Code from scratch)
Any help would be greatly appreciated!
It's a bug that will be fixed in the 2018.9.1 release of the Python extension.
I can't for the life of me figure out what is causing this very odd error.
I am running a script in python 2.7 in the spyder IDE for windows 7. It uses datetime.datetime.strptime at one point. I can run the code once and it seems fine (although I haven't finished debugging, so exceptions have been raised and it hasn't completed normally yet), then if I try running it again I get the following (end of traceback only is shown):
File "C:\path\to\test.py", line 220, in std_imp
self.data[key].append(dt.datetime.strptime(string_var, string_format_var))
ImportError: Failed to import _strptime because the import lockis held by another thread.
I am not running multiple threads with Threading etc. The only way to get the code to make it past this point is to completely restart the computer. Restarting spyder won't work. Web searches haven't seemed to yield any clues or indications of others who have had this happen.
Does anyone understand what is going on? Is this some sort of GIL problem? What is the import lock, and why does it seem to be preventing me from importing this method of the datetime module once I have already tried running the code once?
The solution, as noted by mfitzp, was to include a dummy call to datetime.datetime.strptime at the beginning of the script.
e.g.
# This is a throwaway variable to deal with a python bug
throwaway = datetime.datetime.strptime('20110101','%Y%m%d')