🌐 Mailman 3 October 2020 - Python-list - python.org

Re: Is there a log file that tracks every statement that is being executed when a program is running?
by Mladen Gogala Oct. 25, 2020

Oct. 25, 2020

On Sun, 25 Oct 2020 12:14:52 +0100, Maxime S wrote: > Hi, > > You can use the trace module for that: > https://docs.python.org/3.8/library/trace.html > > Personally I tend to put print statement at strategic places instead, I > find that easier to analyse than a full trace but YMMV. > > Maxime Thank you. I am a YAPN (yet another Python newbie) and this helps me a lot. -- Mladen Gogala Database Consultant http://mgogala.byethost5.com

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Is there a log file that tracks every statement that is being executed when a program is running?
by Steve Oct. 25, 2020

Oct. 25, 2020

This would seriously help troubleshooting for me. I updated a data file and now my main program is choking on it. When the program encounters an error, it dumps a bit of information to the screen for a few steps before the error but that is not enough. Footnote: English sprakers on a roller coaster: "Weeee" Spanish speakers on a rollercoaster: " Nosostros" -----Original Message----- From: Python-list <python-list-bounces+gronicus=sga.ninja(a)python.org> On Behalf Of shrimp_banana Sent: Saturday, October 17, 2020 9:47 PM To: python-list(a)python.org Subject: Re: File Name issue On 10/17/20 4:12 PM, Steve wrote: > The line: > with open("HOURLYLOG.txt", 'r') as infile: > works but, when I rename the file, the line: > with open("HOURLY-LOG.txt", 'r') as infile: > does not. The complaint is: Cannot Assign to operator > > However, I have: > BPM_O2s=open("BPM-O2-Readings.txt","a") > And it works. > > At first, I thought the issue was due to having the - in the filename. > > Is there a fix or explanation for this? > Steve I am unsure if this will help but you could try putting an r in front of the quotes to make it take raw data only. ie. with open(r"HOURLY-LOG.txt", 'r') as infile -- https://mail.python.org/mailman/listinfo/python-list

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Re: Covariance matrix syntax
by Greg Ewing Oct. 24, 2020

Oct. 24, 2020

On 25/10/20 4:49 am, Meghna Karkera wrote: > Is there any syntax for covariance which uses the unbiased formula > (yi-ymean)*(yj-ymean) /n...Monte Carlo method I think you have "biased" and "unbiased" backwards. The formula with n-1 is used when you want to calculate an *unbiased* estimate for a population given a sample of that population. The formula with n is used when your data consists of the entire population. Which situation do you have? (I think the "bias" parameter to numpy.cov is badly named, btw. If you're using it appropriately, setting biased=True does *not* make your result biased -- quite the contrary!) -- Greg

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Re: Covariance matrix syntax
by Christian Gollwitzer Oct. 24, 2020

Oct. 24, 2020

Am 13.10.20 um 06:52 schrieb Meghna Karkera: > Could you let me know what is the back end calculation of this covariance > matrix syntax np.cov > You can look it up yourself: Go to the docs https://numpy.org/doc/stable/reference/generated/numpy.cov.html At the right hand side, just right of the function signature, there is a link [source]. Click there and it takes you to the implementation. Apparently it is done in straightforward Python. Christian PS: Snipped a lot of unrelated citation at the bottom > On Tue, Oct 13, 2020, 10:14 Bruno P. Kinoshita <brunodepaulak(a)yahoo.com.br> > wrote: > [...] >> I think the np.cov is from the numpy module (imported/aliased as np?).

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Debugging a memory leak
by Pasha Stetsenko Oct. 23, 2020

Oct. 23, 2020

Dear Python gurus, I'm a maintainer of a python library "datatable" (can be installed from PyPi), and i've been recently trying to debug a memory leak that occurs in my library. The program that exposes the leak is quite simple: ``` import datatable as dt import gc # just in case def leak(n=10**7): for i in range(n): z = dt.update() leak() gc.collect() input("Press enter") ``` Note that despite the name, the `dt.update` is actually a class, though it is defined via Python C API. Thus, this script is expected to create and then immediately destroy 10 million simple python objects. The observed behavior, however, is that the script consumes more and more memory, eventually ending up at about 500M. The amount of memory the program ends up consuming is directly proportional to the parameter `n`. The `gc.get_objects()` does not show any extra objects however. The `tracemalloc` module shows that there are indeed `n` objects leaked in the `z=dt.update()` line, but doesn't give any extra details. In order to dig deeper, I let the process wait on the "input()" line, and wrote a script to dump the process' memory into a file. Then I scanned through the file looking at any repeated patterns of 64-bit words. Inside the memory dump, the following sequences were the most common: ``` 0x0000000000000000 - 28660404 0x00000001024be6e8 - 4999762 0x0000000101cbdea0 - 119049 0x0000000000000054 - 59537 0x00000fd000000ff0 - 59526 0x0000000000000001 - 16895 0xffffffffffffffff - 12378 ... ``` The most suspicious sequence here is 0x00000001024be6e8, which if you look at that address with lldb, is the address of the PyTypeObject "dt.update", which looks approximately like this: ``` (lldb) p *(PyTypeObject*)(0x000000010f4206e8) (PyTypeObject) $0 = { ob_base = { ob_base = { ob_refcnt = 8 ob_type = 0x000000010ec216b0 } ob_size = 0 } tp_name = 0x000000010f3a442c "datatable.update" tp_basicsize = 48 tp_itemsize = 0 tp_dealloc = 0x000000010f0a8040 (_datatable.cpython-36m-darwin.so`void py::_safe_dealloc<py::oupdate::oupdate_pyobject, &(py::oupdate::oupdate_pyobject::m__dealloc__())>(_object*) at xobject.h:270) tp_print = 0x0000000000000000 tp_getattr = 0x0000000000000000 tp_setattr = 0x0000000000000000 tp_as_async = 0x0000000000000000 tp_repr = 0x000000010eab3fa0 (Python`object_repr) tp_as_number = 0x0000000000000000 tp_as_sequence = 0x0000000000000000 tp_as_mapping = 0x0000000000000000 tp_hash = 0x000000010eb48640 (Python`_Py_HashPointer) tp_call = 0x0000000000000000 tp_str = 0x000000010eab40d0 (Python`object_str) tp_getattro = 0x000000010eaa1ae0 (Python`PyObject_GenericGetAttr) tp_setattro = 0x000000010eaa1ce0 (Python`PyObject_GenericSetAttr) tp_as_buffer = 0x0000000000000000 tp_flags = 266240 ... ``` Thus, I can be quite certain that 0x1024be6e8 is the address of the `dt.update` type structure. The way this address appears in the memory dump looks like this: ``` 0x7f97875cbb10: 0x00000000 0x00000000 0x024be6e8 0x00000001 0x7f97875cbb20: 0x00000000 0x00000000 0x00000000 0x00000000 0x7f97875cbb30: 0x00000000 0x00000000 0x00000000 0x00000000 0x7f97875cbb40: 0x00000000 0x00000000 0x024be6e8 0x00000001 0x7f97875cbb50: 0x00000000 0x00000000 0x00000000 0x00000000 0x7f97875cbb60: 0x00000000 0x00000000 0x00000000 0x00000000 0x7f97875cbb70: 0x00000000 0x00000000 0x024be6e8 0x00000001 0x7f97875cbb80: 0x00000000 0x00000000 0x00000000 0x00000000 0x7f97875cbb90: 0x00000000 0x00000000 0x00000000 0x00000000 0x7f97875cbba0: 0x00000000 0x00000000 0x024be6e8 0x00000001 0x7f97875cbbb0: 0x00000000 0x00000000 0x00000000 0x00000000 0x7f97875cbbc0: 0x00000000 0x00000000 0x00000000 0x00000000 ``` If i guess that all these represent the leaked objects, then inspecting any of them shows the following: ``` (lldb) p *(PyObject*)(0x7f97875cbb10) (PyObject) $2 = { ob_refcnt = 0 ob_type = 0x000000010f4206e8 } ``` Thus, the object didn't actually "leak" in the normal sense: its refcount is 0 and it was reclaimed by the Python runtime (when i print a debug message in tp_dealloc, i see that the destructor gets called every time). Still, Python keeps requesting more and more memory from the system instead of reusing the memory that was supposed to be freed. I'm currently not sure where to go from here. Is there something wrong with my python object that prevents it from being correctly processed by the Python runtime? Because this doesn't seem to be the usual case of incrementing the refcount too many times. This behavior was observed in Python 3.6.6 and also Python 3.8.0b2.

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Question on ABC classes
by Julio Di Egidio Oct. 23, 2020

Oct. 23, 2020

Hello guys, I am professional programmer but quite new to Python, and I am trying to get the grips of some peculiarities of the language. Here is a basic question: if I define an ABC class, I can still instantiate the class unless there are abstract methods defined in the class. (In the typical OO language the class would be not instantiable, period, since it's "abstract". But this is not so in Python, to the point that, also for uniformity, I am feeling compelled to define an @abstractmethod __init__ in my ABC classes, whether they need one or not, and whether there are other abstract methods in the class or not.) Now, I do read in the docs that that is as intended, but I am not understanding the rationale of it: why only if there are abstract methods defined in an ABC class is instantiation disallowed? IOW, why isn't subclassing from ABC enough? Thanks for any enlightenment, Julio

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Re: GUI (tkinter) popularity and job prospects for
by Christian Gollwitzer Oct. 23, 2020

Oct. 23, 2020

Am 22.10.20 um 23:52 schrieb Paul Rubin: > Michael Torrie <torriem(a)gmail.com> writes: >> I doubt you'll find any jobs connected a particular Python GUI toolkit. > It would be really nice if there was a way to straightforwardly run > Tkinter applications on Android. You'd install a single .apk and that > would let you run your Tkinter apps and make launchers for them. It's not unrealistic - there is AndroWish to run Tcl/Tk on Android including GUI and connection to Android specific services (subcommand "borg"). Someone in the Python community would need to make the Tkinter bridge with a native Python for Android. https://www.androwish.org/home/home Christian

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Logic Bank
by gMail Oct. 23, 2020

Oct. 23, 2020

Hello, All I am pleased to announce the release of Logic Bank. Logic Bank introduces spreadsheet-like rules for multi-table derivation and constraint logic for SQLAchemy databases - 40X more concise than legacy code, extensible and manageable using Python. Described in this article <https://dzone.com/articles/automate-business-logic-with-logic-bank>, open source on git. <https://github.com/valhuber/logicbank>

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Issue with Python
by Ifeanyi Obinelo Oct. 23, 2020

Oct. 23, 2020

Hello! I am a Python programmer and I love the language. However, I installed Python 3.9 and suddenly, pip does not install Python libraries anymore. It says that I need Visual Studio C++ 2014 and exits with: "ERROR: Command errored out with exit status 1:..error: Microsoft Visual C++ 14.0 is required. Get it with "Build Tools for Visual Studio": https://visualstudio.microsoft.com/downloads/" (The complete output is about 302 lines long. I will attach at the end of the email.) But I never needed Visual C++ 14 to install modules. Plus I have a bunch of C++ redistributables (but not 14). Is there any thing I can do to fix this? Also, is there any way to carry over my libraries and modules from my previous Python installation (Python 3.8.5)? Or do I need to manually reinstall them? Thank you for your help. Python is awesome! CMD OUTPUT BELOW... C:\Users\USER-1>pip install pandas Defaulting to user installation because normal site-packages is not writeable Collecting pandas Using cached pandas-1.1.3.tar.gz (5.2 MB) Installing build dependencies ... error ERROR: Command errored out with exit status 1: command: 'c:\program files\python39\python.exe' 'c:\program files\python39\lib\site-packages\pip' install --ignore-installed --no-user --prefix 'C:\Users\USER-1\AppData\Local\Temp\pip-build-env-mhg8fpe_\overlay' --no-warn-script-location --no-binary :none: --only-binary :none: -i https://pypi.org/simple -- setuptools wheel 'Cython>=0.29.21,<3' 'numpy==1.15.4; python_version=='"'"'3.6'"'"' and platform_system!='"'"'AIX'"'"'' 'numpy==1.15.4; python_version=='"'"'3.7'"'"' and platform_system!='"'"'AIX'"'"'' 'numpy==1.17.3; python_version>='"'"'3.8'"'"' and platform_system!='"'"'AIX'"'"'' 'numpy==1.16.0; python_version=='"'"'3.6'"'"' and platform_system=='"'"'AIX'"'"'' 'numpy==1.16.0; python_version=='"'"'3.7'"'"' and platform_system=='"'"'AIX'"'"'' 'numpy==1.17.3; python_version>='"'"'3.8'"'"' and platform_system=='"'"'AIX'"'"'' cwd: None Complete output (302 lines): Ignoring numpy: markers 'python_version == "3.6" and platform_system != "AIX"' don't match your environment Ignoring numpy: markers 'python_version == "3.7" and platform_system != "AIX"' don't match your environment Ignoring numpy: markers 'python_version == "3.6" and platform_system == "AIX"' don't match your environment Ignoring numpy: markers 'python_version == "3.7" and platform_system == "AIX"' don't match your environment Ignoring numpy: markers 'python_version >= "3.8" and platform_system == "AIX"' don't match your environment Collecting setuptools Using cached setuptools-50.3.2-py3-none-any.whl (785 kB) Collecting wheel Using cached wheel-0.35.1-py2.py3-none-any.whl (33 kB) Collecting Cython<3,>=0.29.21 Using cached Cython-0.29.21-py2.py3-none-any.whl (974 kB) Collecting numpy==1.17.3 Using cached numpy-1.17.3.zip (6.4 MB) Using legacy 'setup.py install' for numpy, since package 'wheel' is not installed. Installing collected packages: setuptools, wheel, Cython, numpy Running setup.py install for numpy: started Running setup.py install for numpy: finished with status 'error' ERROR: Command errored out with exit status 1: command: 'c:\program files\python39\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\\Users\\USER-1\\AppData\\Local\\Temp\\pip-install-vtk9r3ug\\numpy\\setup.py'"'"'; __file__='"'"'C:\\Users\\USER-1\\AppData\\Local\\Temp\\pip-install-vtk9r3ug\\numpy\\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record 'C:\Users\USER-1\AppData\Local\Temp\pip-record-1i78k7r5\install-record.txt' --single-version-externally-managed --prefix 'C:\Users\USER-1\AppData\Local\Temp\pip-build-env-mhg8fpe_\overlay' --compile --install-headers 'C:\Users\USER-1\AppData\Local\Temp\pip-build-env-mhg8fpe_\overlay\Include\numpy' cwd: C:\Users\USER-1\AppData\Local\Temp\pip-install-vtk9r3ug\numpy\ Complete output (277 lines): Running from numpy source directory. Note: if you need reliable uninstall behavior, then install with pip instead of using `setup.py install`: - `pip install .` (from a git repo or downloaded source release) - `pip install numpy` (last NumPy release on PyPi) blas_opt_info: blas_mkl_info: No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries mkl_rt not found in ['c:\\program files\\python39\\lib', 'C:\\', 'c:\\program files\\python39\\libs'] NOT AVAILABLE blis_info: No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries blis not found in ['c:\\program files\\python39\\lib', 'C:\\', 'c:\\program files\\python39\\libs'] NOT AVAILABLE openblas_info: No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries openblas not found in ['c:\\program files\\python39\\lib', 'C:\\', 'c:\\program files\\python39\\libs'] get_default_fcompiler: matching types: '['gnu', 'intelv', 'absoft', 'compaqv', 'intelev', 'gnu95', 'g95', 'intelvem', 'intelem', 'flang']' customize GnuFCompiler Could not locate executable g77 Could not locate executable f77 customize IntelVisualFCompiler Could not locate executable ifort Could not locate executable ifl customize AbsoftFCompiler Could not locate executable f90 customize CompaqVisualFCompiler Could not locate executable DF customize IntelItaniumVisualFCompiler Could not locate executable efl customize Gnu95FCompiler Could not locate executable gfortran Could not locate executable f95 customize G95FCompiler Could not locate executable g95 customize IntelEM64VisualFCompiler customize IntelEM64TFCompiler Could not locate executable efort Could not locate executable efc customize PGroupFlangCompiler Could not locate executable flang don't know how to compile Fortran code on platform 'nt' NOT AVAILABLE atlas_3_10_blas_threads_info: Setting PTATLAS=ATLAS No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries tatlas not found in ['c:\\program files\\python39\\lib', 'C:\\', 'c:\\program files\\python39\\libs'] NOT AVAILABLE atlas_3_10_blas_info: No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries satlas not found in ['c:\\program files\\python39\\lib', 'C:\\', 'c:\\program files\\python39\\libs'] NOT AVAILABLE atlas_blas_threads_info: Setting PTATLAS=ATLAS No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries ptf77blas,ptcblas,atlas not found in ['c:\\program files\\python39\\lib', 'C:\\', 'c:\\program files\\python39\\libs'] NOT AVAILABLE atlas_blas_info: No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries f77blas,cblas,atlas not found in ['c:\\program files\\python39\\lib', 'C:\\', 'c:\\program files\\python39\\libs'] NOT AVAILABLE accelerate_info: NOT AVAILABLE C:\Users\USER-1\AppData\Local\Temp\pip-install-vtk9r3ug\numpy\numpy\distutils\system_info.py:690: UserWarning: Optimized (vendor) Blas libraries are not found. Falls back to netlib Blas library which has worse performance. A better performance should be easily gained by switching Blas library. self.calc_info() blas_info: No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries blas not found in ['c:\\program files\\python39\\lib', 'C:\\', 'c:\\program files\\python39\\libs'] NOT AVAILABLE C:\Users\USER-1\AppData\Local\Temp\pip-install-vtk9r3ug\numpy\numpy\distutils\system_info.py:690: UserWarning: Blas (http://www.netlib.org/blas/) libraries not found. Directories to search for the libraries can be specified in the numpy/distutils/site.cfg file (section [blas]) or by setting the BLAS environment variable. self.calc_info() blas_src_info: NOT AVAILABLE C:\Users\USER-1\AppData\Local\Temp\pip-install-vtk9r3ug\numpy\numpy\distutils\system_info.py:690: UserWarning: Blas (http://www.netlib.org/blas/) sources not found. Directories to search for the sources can be specified in the numpy/distutils/site.cfg file (section [blas_src]) or by setting the BLAS_SRC environment variable. self.calc_info() NOT AVAILABLE 'svnversion' is not recognized as an internal or external command, operable program or batch file. non-existing path in 'numpy\\distutils': 'site.cfg' lapack_opt_info: lapack_mkl_info: No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries mkl_rt not found in ['c:\\program files\\python39\\lib', 'C:\\', 'c:\\program files\\python39\\libs'] NOT AVAILABLE openblas_lapack_info: No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries openblas not found in ['c:\\program files\\python39\\lib', 'C:\\', 'c:\\program files\\python39\\libs'] NOT AVAILABLE openblas_clapack_info: No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries openblas,lapack not found in ['c:\\program files\\python39\\lib', 'C:\\', 'c:\\program files\\python39\\libs'] NOT AVAILABLE flame_info: No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries flame not found in ['c:\\program files\\python39\\lib', 'C:\\', 'c:\\program files\\python39\\libs'] NOT AVAILABLE atlas_3_10_threads_info: Setting PTATLAS=ATLAS No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries lapack_atlas not found in c:\program files\python39\lib No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries tatlas,tatlas not found in c:\program files\python39\lib No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries lapack_atlas not found in C:\ No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries tatlas,tatlas not found in C:\ No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries lapack_atlas not found in c:\program files\python39\libs No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries tatlas,tatlas not found in c:\program files\python39\libs <class 'numpy.distutils.system_info.atlas_3_10_threads_info'> NOT AVAILABLE atlas_3_10_info: No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries lapack_atlas not found in c:\program files\python39\lib No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries satlas,satlas not found in c:\program files\python39\lib No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries lapack_atlas not found in C:\ No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries satlas,satlas not found in C:\ No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries lapack_atlas not found in c:\program files\python39\libs No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries satlas,satlas not found in c:\program files\python39\libs <class 'numpy.distutils.system_info.atlas_3_10_info'> NOT AVAILABLE atlas_threads_info: Setting PTATLAS=ATLAS No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries lapack_atlas not found in c:\program files\python39\lib No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries ptf77blas,ptcblas,atlas not found in c:\program files\python39\lib No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries lapack_atlas not found in C:\ No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries ptf77blas,ptcblas,atlas not found in C:\ No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries lapack_atlas not found in c:\program files\python39\libs No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries ptf77blas,ptcblas,atlas not found in c:\program files\python39\libs <class 'numpy.distutils.system_info.atlas_threads_info'> NOT AVAILABLE atlas_info: No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries lapack_atlas not found in c:\program files\python39\lib No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries f77blas,cblas,atlas not found in c:\program files\python39\lib No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries lapack_atlas not found in C:\ No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries f77blas,cblas,atlas not found in C:\ No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries lapack_atlas not found in c:\program files\python39\libs No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries f77blas,cblas,atlas not found in c:\program files\python39\libs <class 'numpy.distutils.system_info.atlas_info'> NOT AVAILABLE lapack_info: No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils customize MSVCCompiler libraries lapack not found in ['c:\\program files\\python39\\lib', 'C:\\', 'c:\\program files\\python39\\libs'] NOT AVAILABLE C:\Users\USER-1\AppData\Local\Temp\pip-install-vtk9r3ug\numpy\numpy\distutils\system_info.py:1712: UserWarning: Lapack (http://www.netlib.org/lapack/) libraries not found. Directories to search for the libraries can be specified in the numpy/distutils/site.cfg file (section [lapack]) or by setting the LAPACK environment variable. if getattr(self, '_calc_info_{}'.format(lapack))(): lapack_src_info: NOT AVAILABLE C:\Users\USER-1\AppData\Local\Temp\pip-install-vtk9r3ug\numpy\numpy\distutils\system_info.py:1712: UserWarning: Lapack (http://www.netlib.org/lapack/) sources not found. Directories to search for the sources can be specified in the numpy/distutils/site.cfg file (section [lapack_src]) or by setting the LAPACK_SRC environment variable. if getattr(self, '_calc_info_{}'.format(lapack))(): NOT AVAILABLE c:\program files\python39\lib\distutils\dist.py:274: UserWarning: Unknown distribution option: 'define_macros' warnings.warn(msg) running install running build running config_cc unifing config_cc, config, build_clib, build_ext, build commands --compiler options running config_fc unifing config_fc, config, build_clib, build_ext, build commands --fcompiler options running build_src build_src building py_modules sources creating build creating build\src.win-amd64-3.9 creating build\src.win-amd64-3.9\numpy creating build\src.win-amd64-3.9\numpy\distutils building library "npymath" sources No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils error: Microsoft Visual C++ 14.0 is required. Get it with "Build Tools for Visual Studio": https://visualstudio.microsoft.com/downloads/ ---------------------------------------- ERROR: Command errored out with exit status 1: 'c:\program files\python39\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\\Users\\USER-1\\AppData\\Local\\Temp\\pip-install-vtk9r3ug\\numpy\\setup.py'"'"'; __file__='"'"'C:\\Users\\USER-1\\AppData\\Local\\Temp\\pip-install-vtk9r3ug\\numpy\\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record 'C:\Users\USER-1\AppData\Local\Temp\pip-record-1i78k7r5\install-record.txt' --single-version-externally-managed --prefix 'C:\Users\USER-1\AppData\Local\Temp\pip-build-env-mhg8fpe_\overlay' --compile --install-headers 'C:\Users\USER-1\AppData\Local\Temp\pip-build-env-mhg8fpe_\overlay\Include\numpy' Check the logs for full command output. WARNING: You are using pip version 20.2.3; however, version 20.2.4 is available. You should consider upgrading via the 'c:\program files\python39\python.exe -m pip install --upgrade pip' command. ---------------------------------------- ERROR: Command errored out with exit status 1: 'c:\program files\python39\python.exe' 'c:\program files\python39\lib\site-packages\pip' install --ignore-installed --no-user --prefix 'C:\Users\USER-1\AppData\Local\Temp\pip-build-env-mhg8fpe_\overlay' --no-warn-script-location --no-binary :none: --only-binary :none: -i https://pypi.org/simple -- setuptools wheel 'Cython>=0.29.21,<3' 'numpy==1.15.4; python_version=='"'"'3.6'"'"' and platform_system!='"'"'AIX'"'"'' 'numpy==1.15.4; python_version=='"'"'3.7'"'"' and platform_system!='"'"'AIX'"'"'' 'numpy==1.17.3; python_version>='"'"'3.8'"'"' and platform_system!='"'"'AIX'"'"'' 'numpy==1.16.0; python_version=='"'"'3.6'"'"' and platform_system=='"'"'AIX'"'"'' 'numpy==1.16.0; python_version=='"'"'3.7'"'"' and platform_system=='"'"'AIX'"'"'' 'numpy==1.17.3; python_version>='"'"'3.8'"'"' and platform_system=='"'"'AIX'"'"'' Check the logs for full command output. WARNING: You are using pip version 20.2.3; however, version 20.2.4 is available. You should consider upgrading via the 'c:\program files\python39\python.exe -m pip install --upgrade pip' command.

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Re: Basic Python help
by mikael petterson Oct. 23, 2020

Oct. 23, 2020

fredag 23 oktober 2020 kl. 13:22:55 UTC+2 skrev Frank Millman: > On 2020-10-23 12:41 PM, mikael petterson wrote: > > Hi, > > > > I need to use the following code but in java. > > > > END_DELIM = '\n##\n' > > def start_delim(data_len): return '\n#%s\n' % (data_len) > > data = "%s%s%s" % (start_delim(len(data)), data, END_DELIM) > > > > Can anyone help me to understand what it means: > > > > I am guessing now: > > > > a function defined "start_delim" takes the length of a data string. > > function does modulo on something. This something I am not sure of > > :-) > > Does '\n#%s\n' will this be evaluated to a number when %s i replaced with data_len? > > > > Then the result is used as one parameter in "%s%s%s" > > start_delim then for the other > > data > > END_DELIM > > > I think it is simpler than that. > > >>> > >>> '\n#%s\n' % 2 > '\n#2\n' > >>> > > All it is doing is replacing '%s' with the length of the string. > > So the result is the concatenation of - > > 1. '\n' + '#' + length of string + '\n' as the start delimiter > > 2. the string itself > > 3. '\n' + '#' + '#' + '\n' as the end delimiter > > Frank Millman Yes that was simpler than I thought. Thanks a lot!

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