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

Can Python call and use FME modules and functions such as StreamOrderCalculator?
by Shaozhong SHI Dec. 23, 2021

Dec. 23, 2021

Can we do something like import an fme.something and make use of FME modules and functions? Regards, David

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Advanced ways to get object information from within python
by Julius Hamilton Dec. 23, 2021

Dec. 23, 2021

Hello, I would like to significantly increase my abilities to find the information I am seeking about any Python object I am using from within Python. I find this to be a really essential skill set. After reading documentation, it really helps to get under the hood at the command line and start testing your own competence by examining all the methods and classes, and their arguments and return types and so on. I was hoping someone could help me fill in more details about what I currently know. I'd like to use Scrapy as an example, since it's a library I'm currently learning. import scrapy I assume I'll start with "dir", as it's the most convenient. dir(scrapy) shows this: ['Field', 'FormRequest', 'Item', 'Request', 'Selector', 'Spider', '__all__', '__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__path__', '__spec__', '__version__', '_txv', 'exceptions', 'http', 'item', 'link', 'linkextractors', 'selector', 'signals', 'spiders', 'twisted_version', 'utils', 'version_info'] I wish there was a convenient way for me to know what all of these are. I understand "dir" shows everything from the namespace - so that includes methods which are present only because they are imported from other modules, by this module. Let's assume at minimum I know that I should be able to call all these "attributes" (I believe this is what Python calls them - an attribute can be anything, a method, a variable, etc. But then, how to distinguish between this general notion of an "attribute" vs a specific attribute of a class? Or is that called a "property" or something?) I can confirm that every single name in the above list works when I call it from scrapy, like this: >>> scrapy.Field <class 'scrapy.item.Field'> >>> scrapy.utils <module 'scrapy.utils' from '/usr/local/lib/python3.9/dist-packages/scrapy/utils/__init__.py'> But I can't conveniently iterate over all of these to see all their types, because dir() returns a list of strings. How can I iterate over all attributes? I can't use "getattr" because that requires you to enter the name of what you're looking for. I would like to spit out all attributes with their types, so I can know what my options are in more detail than dir() provides. This is basically a dead-end for me until someone can illuminate this strategy I'm pursuing, so now I'd like to focus on inspect and help. inspect.getmembers is useful in principle, but I find the results to give information overload. This is just an excerpt of what it returns: pprint.pprint(inspect.getmembers(scrapy)) [('Field', <class 'scrapy.item.Field'>), ('Selector', <class 'scrapy.selector.unified.Selector'>), ('Spider', <class 'scrapy.spiders.Spider'>), ('__all__', ['__version__', 'version_info', 'twisted_version', 'Spider', Why does it just list the name and type for some classes, but for others goes on to a sublist? __all__ does not list any type in adjacent angular brackets, it just goes on to list some attributes without any information about what they are. Can I suppress sublists from being printed with inspect.getmethods? Or can I recursively require sublists also display their type? Lastly, the "help" function. I find "help" to similarly be a situation of information overload. Again, it starts with a list of "package contents". I'm not sure I see the use of this long list of names, without much description of what they are. Next, it lists "classes", but I don't understand: builtins.dict(builtins.object) scrapy.item.Field parsel.selector.Selector(builtins.object) scrapy.selector.unified.Selector(parsel.selector.Selector, scrapy.utils.trackref.object_ref) What determines the order of these classes - the order in which they appear in the source code? What about the indentation? builtins.dict() is a Python builtin. Then why is it listed inside of Scrapy's "help" - are all builtins necessarily listed inside a class or just the builtins it specifically imported or inherited? My best guess is the most indented lines are what is actually written in the class, the lines above are just listing the inheritance? So scrapy.item.Field inherits the Python dictionary class, and it does this because that way you can treat the class like a dictionary sometimes, using dictionary methods and so on? class Field(builtins.dict) | Container of field metadata | | Method resolution order: | Field | builtins.dict | builtins.object | | Data descriptors defined here: What are data descriptors? I understand IDE's tend to just print the docstring of a method as a sort of overlay while you are writing with it, but I'm not able to use the __docstring__ variable well - scrapy.__docstring__, scrapy.Spider.__docstring__, and so on, return "object has no attribute __docstring__". I'm really fond of inspect.getsource(), all else failing, though - that's very clear and insightful. There's more to learn but that's enough questions for now. I'd really appreciate anybody helping me find effective ways of investigating modules, classes and methods from the command line. Thanks very much, Julius

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Sir jupyter note book is not working on my laptop?
by IMTIAZ AHMAD Dec. 23, 2021

Dec. 23, 2021

Sent from [1]Mail for Windows References Visible links 1. https://go.microsoft.com/fwlink/?LinkId=550986

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Re: Advanced ways to get object information from within python
by Robert Latest Dec. 23, 2021

Dec. 23, 2021

Julius Hamilton wrote: > dir(scrapy) shows this: > > ['Field', 'FormRequest', 'Item', 'Request', 'Selector', 'Spider', > '__all__', '__builtins__', '__cached__', '__doc__', '__file__', > '__loader__', '__name__', '__package__', '__path__', '__spec__', > '__version__', '_txv', 'exceptions', 'http', 'item', 'link', > 'linkextractors', 'selector', 'signals', 'spiders', 'twisted_version', > 'utils', 'version_info'] > > I wish there was a convenient way for me to know what all of these are. ['%s: %s' % (x, type(getattr(scrapy, x))) for x in dir(scrapy)]

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Py_TRASHCAN_SAFE_BEGIN/END in C extension?
by Marco Sulla Dec. 22, 2021

Dec. 22, 2021

In Python 3.7, must Py_TRASHCAN_SAFE_BEGIN - Py_TRASHCAN_SAFE_END be used in a C extension? I'm asking because in my C extension I use them in the deallocator without problems, but users signalled me that they segfault in Python 3.7 on Debian 10. I checked and this is true.

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Call julia from Python: which package?
by Albert-Jan Roskam Dec. 22, 2021

Dec. 22, 2021

Hi, I have a Python program that uses Tkinter for its GUI. It's rather slow so I hope to replace many or all of the non-GUI parts by Julia code. Has anybody experience with this? Any packages you can recommend? I found three alternatives: * https://pyjulia.readthedocs.io/en/latest/usage.html# * https://pypi.org/project/juliacall/ * https://github.com/JuliaPy/PyCall.jl Thanks in advance! Albert-Jan

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print('\N{flag: Mauritius}') not supported in py3.9
by Abdur-Rahmaan Janhangeer Dec. 22, 2021

Dec. 22, 2021

Mike Driscoll printed this on Twitter >>> print('\N{Sauropod}') 🦕 Using py3.9 i got the above. I found the whole CLDR short name here: https://unicode.org/emoji/charts/full-emoji-list.html However when i do >>> print('\N{flag: Mauritius}') File "<stdin>", line 1 print('\N{flag: Mauritius}') ^ i get SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 0-18: unknown Unicode character name So is it that Python3.9 does not support it or what is the issue here? Thanks Kind Regards, Abdur-Rahmaan Janhangeer about <https://compileralchemy.github.io/> | blog <https://www.pythonkitchen.com> github <https://github.com/Abdur-RahmaanJ> Mauritius

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'array.array' object has no attribute 'tostring' which 3 got it fixed?
by '2+ Dec. 21, 2021

Dec. 21, 2021

hi ;) got popos installed on my raspberry pi4 and it is currently running python 3.9.7 i get this error when running my script: 'array.array' object has no attribute 'tostring' this bug seems to be pretty old .. how long should i be waiting to get it fixed with apt upgrade? or should i use other attribute instead?

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[Python-announce] Benchmark Smil vs Scikit-image (morphological features)
by Jose-Marcio Martins da Cruz Dec. 20, 2021

Dec. 20, 2021

Hello, We've done a comparative benchmark (speed and memory usage) with Smil and Scikit-Image. Smil is a mathematical morphology dedicated library of functions. So comparisons are done only on this area. We've been working on Mathematical Morphology for more than 50 years now the discipline was created here at our research department in the sixties. Smil inherits the experience of previous libraries and software we've been writing since the 70's. In just some few words, Smil can be orders of magnitude faster than Scikit-image (hundreds or even thousands) on some operations thanks to parallelization and vectorization (SIMD), depending on the computer architecture. Smil doesn't replace scikit-image but may be a good complement to scikit-image when speed is important. Benchmark results are available at : https://smil.cmm.minesparis.psl.eu/smil-vs-skimage Comments are welcome, Best regards José-Marcio -- --------------------------------------------------------------- Jose Marcio MARTINS DA CRUZ, Ph.D. Ecole des Mines de Paris Centre de Morphologie Mathématique https://orcid.org/0000-0002-2981-7028 --------------------------------------------------------------- Mon livre sur le spam : http://amzn.to/LEscRu ---------------------------------------------------------------

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jupyter console vs. ipython in Emacs
by Pieter van Oostrum Dec. 20, 2021

Dec. 20, 2021

My Python development environment is Emacs. I used to use 'jupyter console --simple-prompt' (driven by Emacs comint) to do interactive work, but it has the disadvantage that it doesn't work properly with multiline input, including pastes. However, I discovered that 'ipython --simple-prompt' in Emacs does work with multiline statements. No idea why jupyter console doesn't. Is there any advantage in using jupyter console over ipython? -- Pieter van Oostrum <pieter(a)vanoostrum.org> www: http://pieter.vanoostrum.org/ PGP key: [8DAE142BE17999C4]

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