🌐 Mailman 3 October 2024 - Python-list - python.org

Re: Correct syntax for pathological re.search()
by Jon Ribbens Oct. 7, 2024

Oct. 7, 2024

On 2024-10-07, Stefan Ram <ram(a)zedat.fu-berlin.de> wrote: > "Michael F. Stemper" <michael.stemper(a)gmail.com> wrote or quoted: >>For now, I'll use the "r" in a cargo-cult fashion, until I decide which >>syntax I prefer. (Is there any reason that one or the other is preferable?) > > I'd totally go with the r-style notation! > > It's got one bummer though - you can't end such a string literal with > a backslash. But hey, no biggie, you could use one of those notations: > > main.py > > path = r'C:\Windows\example' + '\\' > > print( path ) > > path = r''' > C:\Windows\example\ > '''.strip() > > print( path ) > > stdout > > C:\Windows\example\ > C:\Windows\example\ > > . ... although of course in this example you should probably do neither of those things, and instead do: from pathlib import Path path = Path(r'C:\Windows\example') since in a Path the trailing '\' or '/' is unnecessary. Which leaves very few remaining uses for a raw-string with a trailing '\'...

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Re: Correct syntax for pathological re.search()
by Michael F. Stemper Oct. 7, 2024

Oct. 7, 2024

On 07/10/2024 08.56, Stefan Ram wrote: > "Michael F. Stemper" <michael.stemper(a)gmail.com> wrote or quoted: >> if not re.search("\\sout\{", line): > > So, if you're not down to slap an "r" before your string literals, > you're going to end up doubling down on every backslash. Never heard of that before, but it did the trick. > Long story short, those double backslashes in your regex? > They'll be quadrupling up in your Python string literal! > for line in lines: > product = re.search( "\\\\sout\\{", line ) This also worked. For now, I'll use the "r" in a cargo-cult fashion, until I decide which syntax I prefer. (Is there any reason that one or the other is preferable?) Thanks for your help, Mike -- Michael F. Stemper Economists have correctly predicted seven of the last three recessions.

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Re: Beazley's Problem
by Annada Behera Oct. 6, 2024

Oct. 6, 2024

The "next-level math trick" Newton-Raphson has nothing to do with functional programming. I have written solvers in purely iterative style. As far as I know, Newton-Raphson is the opposite of functional programming as you iteratively solve for the root. Functional programming is stateless where you are not allowed to store any state (current best guess root). -----Original Message----- From: Paul Rubin <no.email(a)nospam.invalid> Subject: Re: Beazley's Problem Date: 09/22/2024 01:49:50 AM Newsgroups: comp.lang.python ram(a)zedat.fu-berlin.de (Stefan Ram) writes: > It's hella rad to see you bust out those "next-level math tricks" > with just a single line each! You might like: https://www.cs.kent.ac.uk/people/staff/dat/miranda/whyfp90.pdf The numerics stuff starts on page 9.

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Best Practice Virtual Environment
by Ulrich Goebel Oct. 6, 2024

Oct. 6, 2024

Hi, I learned to use virtual environments where ever possible, and I learned to pip install the required packages there. That works quite nice at home. Now I come to deploy a Python script on a debian linux server, making it usable for a couple of users there. Debian (or even Python3 itself) doesn't allow to pip install required packages system wide, so I have to use virtual environments even there. But is it right, that I have to do that for every single user? Can someone give me a hint to find an howto for that? Best regards Ulrich -- Ulrich Goebel <ml(a)fam-goebel.de>

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How to check whether lip movement is significant using face landmarks in dlib?
by marc nicole Oct. 5, 2024

Oct. 5, 2024

I am trying to assess whether the lips of a person are moving too much while the mouth is closed (to conclude they are chewing). I try to assess the lip movement through landmarks (dlib) : Inspired by the mouth example ( https://github.com/mauckc/mouth-open/blob/master/detect_open_mouth.py#L17), and using it before the following function (as a primary condition for telling the person is chewing), I wrote the following function: def lips_aspect_ratio(shape): # grab the indexes of the facial landmarks for the lip (mStart, mEnd) = (61, 68) lip = shape[mStart:mEnd] print(len(lip)) # compute the euclidean distances between the two sets of # vertical lip landmarks (x, y)-coordinates # to reach landmark 68 I need to get lib[7] not lip[6] (while I get lip[7] I get IndexOutOfBoundError) A = dist.euclidean(lip[1], lip[6]) # 62, 68 B = dist.euclidean(lip[3], lip[5]) # 64, 66 # compute the euclidean distance between the horizontal # lip landmark (x, y)-coordinates C = dist.euclidean(lip[0], lip[4]) # 61, 65 # compute the lip aspect ratio mar = (A + B) / (2.0 * C) # return the lip aspect ratio return mar How to define an aspect ratio for the lips to conclude they are moving significantly? Is the mentioned function able to tell whether the lips are significantly moving while the mouth is closed?

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Python crash together with threads
by Guenther Sohler Oct. 3, 2024

Oct. 3, 2024

My Software project is working fine in most of the cases (www.pythonscad.org) however I am right now isolating a scenario, which makes it crash permanently. It does not happen with Python 3.11.6 (and possibly below), it happens with 3.12 and above It does not happen when not using Threads. However due to the architecture of the program I am forced to evaluate some parts in main thread and some parts in a dedicated Thread. The Thread is started with QThread(QT 5.0) whereas I am quite sure that program flows do not overlap. When I just execute my 1st very simple Python function inside the newly created thread, like: PyObject *a = PyFloat_FromDouble(3.3); my program crashes with this Stack trace 0 0x00007f6837fe000f in _PyInterpreterState_GET () at ./Include/internal/pycore_pystate.h:179 #1 get_float_state () at Objects/floatobject.c:38 #2 PyFloat_FromDouble (fval=3.2999999999999998) at Objects/floatobject.c:136 #3 0x00000000015a021f in python_testfunc() () #4 0x0000000001433301 in CGALWorker::work() () #5 0x0000000000457135 in CGALWorker::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) () #6 0x00007f68364d0f9f in void doActivate<false>(QObject*, int, void**) () at /lib64/libQt5Core.so.5 #7 0x00007f68362e66ee in QThread::started(QThread::QPrivateSignal) () at /lib64/libQt5Core.so.5 #8 0x00007f68362e89c4 in QThreadPrivate::start(void*) () at /lib64/libQt5Core.so.5 #9 0x00007f6835cae19d in start_thread () at /lib64/libc.so.6 #10 0x00007f6835d2fc60 in clone3 () at /lib64/libc.so.6 I suspect, that this is a Null pointer here See also _PyInterpreterState_Get() and _PyGILState_GetInterpreterStateUnsafe(). */ static inline PyInterpreterState* _PyInterpreterState_GET(void) { PyThreadState *tstate = _PyThreadState_GET(); #ifdef Py_DEBUG _Py_EnsureTstateNotNULL(tstate); #endif # <<----------- suspect state is nullpointer return tstate->interp; } any clues , whats going on here, and how I can mitigate that ?

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doRe: Help with Streaming and Chunk Processing for Large JSON Data (60 GB) from Kenna API
by Greg Ewing Oct. 3, 2024

Oct. 3, 2024

On 3/10/24 11:48 am, Left Right wrote: > So, streaming parsers (eg. SAX) are written for a regular language > that approximates XML. SAX doesn't parse a whole XML document, it parses small pieces of it independently and passes them on. It's more like a lexical analyser than a parser in that respect. -- Greg

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Help with Streaming and Chunk Processing for Large JSON Data (60 GB) from Kenna API
by Asif Ali Hirekumbi Oct. 2, 2024

Oct. 2, 2024

Dear Python Experts, I am working with the Kenna Application's API to retrieve vulnerability data. The API endpoint provides a single, massive JSON file in gzip format, approximately 60 GB in size. Handling such a large dataset in one go is proving to be quite challenging, especially in terms of memory management. I am looking for guidance on how to efficiently stream this data and process it in chunks using Python. Specifically, I am wondering if there’s a way to use the requests library or any other libraries that would allow us to pull data from the API endpoint in a memory-efficient manner. Here are the relevant API endpoints from Kenna: - Kenna API Documentation <https://apidocs.kennasecurity.com/reference/welcome> - Kenna Vulnerabilities Export <https://apidocs.kennasecurity.com/reference/retrieve-data-export> If anyone has experience with similar use cases or can offer any advice, it would be greatly appreciated. Thank you in advance for your help! Best regards Asif Ali

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Re: Help with Streaming and Chunk Processing for Large JSON Data (60 GB) from Kenna API
by Greg Ewing Oct. 2, 2024

Oct. 2, 2024

On 1/10/24 8:34 am, Left Right wrote: > You probably forgot that it has to be _streaming_. Suppose you parse > the first digit: can you hand this information over to an external > function to process the parsed data? -- No! because you don't know the > magnitude yet. By that definition of "streaming", no parser can ever be streaming, because there will be some constructs that must be read in their entirety before a suitably-structured piece of output can be emitted. The context of this discussion about integers is the claim that they *could* be parsed incrementally if they were written little endian instead of big endian, but the same argument applies either way. -- Greg

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Re: Python crash together with threads
by Louis Krupp Oct. 2, 2024

Oct. 2, 2024

On 10/2/2024 7:26 AM, Guenther Sohler wrote: > My Software project is working fine in most of the cases > (www.pythonscad.org) > however I am right now isolating a scenario, which makes it crash > permanently. > > It does not happen with Python 3.11.6 (and possibly below), it happens with > 3.12 and above > It does not happen when not using Threads. > > However due to the architecture of the program I am forced to evaluate some > parts in main thread and some parts in a dedicated Thread. The Thread is > started with QThread(QT 5.0) > whereas I am quite sure that program flows do not overlap. > > When I just execute my 1st very simple Python function inside the newly > created thread, like: > > PyObject *a = PyFloat_FromDouble(3.3); > > my program crashes with this Stack trace > > 0 0x00007f6837fe000f in _PyInterpreterState_GET () at > ./Include/internal/pycore_pystate.h:179 > #1 get_float_state () at Objects/floatobject.c:38 > #2 PyFloat_FromDouble (fval=3.2999999999999998) at > Objects/floatobject.c:136 > #3 0x00000000015a021f in python_testfunc() () > #4 0x0000000001433301 in CGALWorker::work() () > #5 0x0000000000457135 in CGALWorker::qt_static_metacall(QObject*, > QMetaObject::Call, int, void**) () > #6 0x00007f68364d0f9f in void doActivate<false>(QObject*, int, void**) () > at /lib64/libQt5Core.so.5 > #7 0x00007f68362e66ee in QThread::started(QThread::QPrivateSignal) () at > /lib64/libQt5Core.so.5 > #8 0x00007f68362e89c4 in QThreadPrivate::start(void*) () at > /lib64/libQt5Core.so.5 > #9 0x00007f6835cae19d in start_thread () at /lib64/libc.so.6 > #10 0x00007f6835d2fc60 in clone3 () at /lib64/libc.so.6 > > > I suspect, that this is a Null pointer here > See also _PyInterpreterState_Get() > and _PyGILState_GetInterpreterStateUnsafe(). */ > static inline PyInterpreterState* _PyInterpreterState_GET(void) { > PyThreadState *tstate = _PyThreadState_GET(); > #ifdef Py_DEBUG > _Py_EnsureTstateNotNULL(tstate); > #endif > # <<----------- suspect state is nullpointer > return tstate->interp; > } > > any clues , whats going on here, and how I can mitigate that ? Can you post a small, self-contained program that demonstrates the problem? Louis

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