🌐 Mailman 3 December 2021 - Python-list - python.org

Re: threading and multiprocessing deadlock
by Johannes Bauer Dec. 6, 2021

Dec. 6, 2021

Am 06.12.21 um 13:56 schrieb Martin Di Paola: > Hi!, in short your code should work. > > I think that the join-joined problem is just an interpretation problem. > > In pseudo code the background_thread function does: > > def background_thread() > # bla > print("join?") > # bla > print("joined") > > When running this function in parallel using threads, you will probably > get a few "join?" first before receiving any "joined?". That is because > the functions are running in parallel. > > The order "join?" then "joined" is preserved within a thread but not > preserved globally. Yes, completely understood and really not the issue. That these pairs are not in sequence is fine. > Now, I see another issue in the output (and perhaps you was asking about > this one): > > join? > join? > myfnc > myfnc > join? > join? > joined. > joined. > > So you have 4 "join?" that correspond to the 4 background_thread > function calls in threads but only 2 "myfnc" and 2 "joined". Exactly that is the issue. Then it hangs. Deadlocked. > Could be possible that the output is truncated by accident? No. This is it. The exact output varies, but when it hangs, it always also does not execute the function (note the lack of "myfnc"). For example: join? join? myfnc join? myfnc join? myfnc joined. joined. joined. (only three threads get started there) join? myfnc join? join? join? joined. (this time only a single one made it) join? join? join? myfnc join? myfnc joined. myfnc joined. joined. (three get started) > I ran the same program and I got a reasonable output (4 "join?", "myfnc" > and "joined"): > > join? > join? > myfnc > join? > myfnc > join? > joined. > myfnc > joined. > joined. > myfnc > joined. This happens to me occasionally, but most of the time one of the processes deadlocks. Did you consistently get four of each? What OS/Python version were you using? > Another issue that I see is that you are not joining the threads that > you spawned (background_thread functions). True, I kindof assumed those would be detached threads. > I hope that this can guide you to fix or at least narrow the issue. Depending on what OS/Python version you're using, that points in that direction and kindof reinforces my belief that the code is correct. Very curious. Thanks & all the best, Joe

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python list files and folder using tkinter
by Pascal B Dec. 5, 2021

Dec. 5, 2021

Hello, I have already posted a message some time ago for this app. Since then, I didn't code in python or made any changes. I think before getting further with functionnalities a few things or the whole thing need to be changed. For exemple, it would need a button to pick folders and maybe ask if the csv resulting file can be saved in the same folder. And more important, files are listing ok in windows but not in linux after running it a few times. https://github.com/barpasc/listfiles code extract without indentation, see source script on github elif vvchkboxF == 1: | # *** FOLDERS AND FILES ONLY *** | | | for root, dirs, files in os.walk(Lpath, topdown=False): | | | ### calcul taille dossier | | | size = 0 | | | for x, y, z in os.walk(root): | | | for i in z: | | | ftmp_che = x + os.sep + i | | | f_size += os.path.getsize(ftmp_che) | | | ### ecriture taille dossier | | | counter = root.count(os.path.sep) - counterPath | | | vfile_name = root | | | vfile_name = vfile_name + os.path.sep | | | vfile_name = os.path.split(os.path.dirname(vfile_name))[1] | | | vfile_name += os.path.sep | | | if counter <= f_vscale: | | | csv_contents += "%s;%s;%.0f;%.2f;%.2f;%.2f;%s\n" % (root, vfile_name, f_size, f_size/1024, f_size/1048576,f_size/1073741824, "folder") | | | | | | ### calcul +ecriture taille fichier | | | for f in os.listdir(Lpath): | | | path = os.path.join(Lpath, f) | | | if os.path.isfile(path): | | | f_size = 0 | | | f_size = os.path.getsize(path) | | | csv_contents += "%s;%s;%.0f;%.2f;%.2f;%.2f;%s\n" % (path, f, f_size, f_size/1024, f_size/1048576,f_size/1073741824, "file") | | | | | | fx_writeCSV_str(csv_contents) | | print("job adv listing files ok")

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ANN: A new library for encryption and signing has been released.
by Vinay Sajip Dec. 5, 2021

Dec. 5, 2021

A new library called pagesign (Python-age-sign) has been released on PyPI [1]. It covers similar functionality to python-gnupg, but uses the modern encryption tool age [2] and the modern signing tool minisign [3]. The initial release allows you to: * Create and manage identities (which are containers for the keys used for encryption/decryption and signing/verification). * Encrypt and decrypt files to multiple recipients. * Sign files and verify signatures. This release has been signed with my code signing key: Vinay Sajip (CODE SIGNING KEY) <vinay_sajip at yahoo.co.uk> Fingerprint: CA74 9061 914E AC13 8E66 EADB 9147 B477 339A 9B86 Recent changes to PyPI don't show the GPG signature with the download links. An alternative download source where the signatures are available is at [4]. Documentation is available at [5]. As always, your feedback is most welcome (especially bug reports [6], patches and suggestions for improvement, or any other points). Enjoy! Cheers Vinay Sajip [1] https://pypi.org/project/pagesign/0.1.0/ [2] https://age-encryption.org/ [3] https://jedisct1.github.io/minisign/ [4] https://bitbucket.org/vinay.sajip/pagesign/downloads/ [5] https://docs.red-dove.com/pagesign/ [6] https://github.com/vsajip/pagesign/issues/new/choose

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Re: TypeError: 'bytes' object is not callable error while trying to converting to bytes.
by Wasia Maya Dec. 5, 2021

Dec. 5, 2021

You have assigned a bytes value to the name bytes: >>> bytes([10, 20, 30, 40]) b'\n\x14\x1e(' >>> bytes = bytes([10, 20, 30, 40]) >>> bytes([10, 20, 30, 40]) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: 'bytes' object is not callable bytes is now bound to the value b'\n\x14\x1e(', which is not callable. This global is shadowing the built-in. Delete it: del bytes

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how I can get python idle?
by nikos petsios Dec. 3, 2021

Dec. 3, 2021

Sent from [1]Mail for Windows 10 [2][IMG] Virus-free. [3]www.avast.com References Visible links 1. https://go.microsoft.com/fwlink/?LinkId=550986 2. https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai… 3. https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…

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A decade or so of Python programming, and I've never thought to "for-elif"
by Chris Angelico Dec. 2, 2021

Dec. 2, 2021

for ns in namespaces: if name in ns: print("Found!") break elif name.isupper(): print("All-caps name that wasn't found") This actually doesn't work. I have been programming in Python for well over a decade, and never before been in a situation where this would be useful. As YAGNIs go, this is right up there. (For the record, since this was the last thing in the function, I just made the break a return. Alternatively, an extra indentation level "else: if name.isupper():" wouldn't have been that terrible.) Your random piece of amusement for today. ChrisA

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NOT ABLE TO SEE PICTURES
by Ragavendar Dec. 2, 2021

Dec. 2, 2021

When the python runs in file explorer when I open a folder it shows NO ITEAMS FOUND and if I open same folder without python ITEAMS ARE THERE so kindly help me Sent from [1]Mail for Windows References Visible links 1. https://go.microsoft.com/fwlink/?LinkId=550986

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Installation of GeoPandas - failed at fiona
by Shaozhong SHI Dec. 1, 2021

Dec. 1, 2021

I am trying to install geopandas. I navigated to c:\programData|Anaconda3\Scripts> and typed in 'pip install geopandas'. It ran but failed at fiona. I tried import geopandas as gp, but Error Message says: No module names 'geopandas'. Can anyone help? Regards, David

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