I have a very simple question:
I failed to find any tutorial on using the Spyder cython console. How should be the cython code used?
On the official site only states that "A Cython console allows you to use the Cython language to speed up your code and call C functions directly from Python." But how?
Following this tutorial I tried to run the setup.py, the hello.pyx, and got errors when trying %cython, %%cython, or cdef in .py or .ipy files.
.c or .cpp files cannot be run at all.
Moreover, when I try to run a file containing simply print("bum") or a = 1 in cython console, nothing happens (it works when written directely to the console).
Many thanks for a little push.
Related
I am using the Sphinx autodoc and napoleon extensions to generate the documentation for my project (Qtools). This works well on my local machines. I am using Sphinx 3.1.2 (or higher). However, when I build the documentation on Read the Docs (RTD), only text added directly to the reStructuredText files that form the source of the documentation is processed. The docstrings that are supposed to be pulled in by autodoc do not appear in the HTML documentation generated by RTD. So for example in docs\source\section2_rsdoc.rst I have:
Response spectra
================
The response spectrum class
---------------------------
.. autoclass:: qtools.ResponseSpectrum
:members:
Response spectrum creation
--------------------------
.. autofunction:: qtools.calcrs
.. autofunction:: qtools.calcrs_cmp
.. autofunction:: qtools.loadrs
See also :func:`qtools.convert2rs` (converts a power spectrum into a response spectrum).
This results in:
Response spectra
The response spectrum class
Response spectrum creation
See also qtools.convert2rs (converts a power spectrum into a response spectrum).
In other words, all directives are apparently ignored, and hyperlinks to other functions are not added. I have examined several basic guidance documents such as this one, but I cannot figure out what I am doing wrong. RTD builds the documentation without any errors or warnings. In RTD advanced settings I have:
Documentation type: Sphinx HTML
Requirements file: requirements.txt
Python interpreter: CPython 3.x
Install Project: no
Use system packages: no
Python configuration file: blank
Enable PDF build: no
Enable EPUB build: no
I haven't touched any other settings.
In conf.py I have tried the following variations of line 15: sys.path.insert(0, os.path.abspath('.')), sys.path.insert(0, os.path.abspath('../..')) and the current sys.path.insert(0, os.path.abspath('../../..')). None of those made any difference.
I would be grateful for any help!
RTD builds the documentation without any errors or warnings
This is slightly incorrect. As you can see in the build logs, autodoc is emitting numerous warnings like this one:
WARNING: autodoc: failed to import class 'ResponseSpectrum' from module 'qtools'; the following exception was raised:
No module named 'qtools'
This has happened for all your variations of sys.path.insert, as you can see in some past builds.
Trying to make it work this way is tricky, since Read the Docs does some magic to guess the directory where your documentation is located, and also the working directory changes between commands.
Instead, there are two options:
Locate where the conf.py is located (see How do you properly determine the current script directory?) and work out a relative package from there.
Invest some time into making your code installable using up-to-date Python packaging standards, for example putting all your sources inside a qtools directory, and creating an appropriate pyproject.toml file using flit.
I'm using the current bundled binaries from https://github.com/excelsior-oss/xds (as of 12/6/2020) with just the most basic Hello World MOD file:
MODULE HelloWorld;
FROM STextIO IMPORT WriteLn, WriteString;
BEGIN
WriteString("Hello, World!");
WriteLn;
END HelloWorld.
xc HelloWorld.mod works fine for compiling it to object. However, I'm not clear on the exact syntax for xlink on a standalone MOD file. xlink HelloWorld.obj will at least get it to try with my object file, but as the error shows, it doesn't know the entrypoint. I've tried setting the entry point with the /ENTRY switch, but no luck doing it by module name. I've also tried setting the /SYS to console, but again, no luck there.
I feel there's some trivial linker option or program directive needed, but I'm just not finding it via Google...
To build a binary, use: xc =a =make HelloWorld.mod
The above is found in https://github.com/excelsior-oss/xds/blob/master/Sources/Doc/Comp/src/usage.tex .
It is unfortunate that XDS did not put PDFs of their documentation on github. I suggest building the documentation from their LaTeX files.
Edit: I since learnt that the Wayback Machine has archived the XDS documentation here: https://web.archive.org/web/20060705213825/http://www.excelsior-usa.com/xdsdoc.html
I wrote a library in Cython that has two different "modes":
If rendering, I compile using GLFW.
If not rendering, I compile using EGL, which is faster, but I have not figured out how to render with it.
What is the recommended way to handle this situation?
Right now, I have the following directory structure:
mujoco
├── __init__.py
├── simEgl.pyx
├── simGlfw.pyx
├── sim.pxd
└── sim.pyx
simEgl.pyx contains EGL code and simGlfw.pyx contains GLFW code. setup.py uses an environment variable to choose one or the other for the build.
This works ok, except that I need to recompile the code every time I want to switch between modes. There must be a better way.
Update
I agree that the best approach is to simultaneously compile two different libraries and use a toggle to choose which one to import. I already do have a base class in sim.pyx with shared functionality. However this base class must itself be compiled with the separate libraries. Specifically, sim.pyx depends on libmujoco.so which depends on either GLFW or EGL.
Here is my exhaustive search of possible approaches:
If I do not compile an extension for sim.pyx, I get ImportError: No module named 'mujoco.sim'
If I compile an extension for sim.pyx without including graphics libraries in the extension, I get ImportError: /home/ethanbro/.mujoco/mjpro150/bin/libmujoco150.so: undefined symbol: __glewBlitFramebuffer
If I compile an extension for sim.pyx and choose one set of graphics libraries (GLFW), then when I try to use the other set of graphics libraries (EGL) this does not work either unsurprisingly:
ERROR: GLEW initalization error: Missing GL version
If I compile two different versions of the sim.pyx library, one with one set of libraries, one with the other, I get: TypeError: unorderable types: dict() < dict() which is not a very helpful error message, but appears to result from trying to share a source file between two different extensions.
Something like option 4 should be possible. In fact, if I were working in raw C, I would simply build two shared objects side by side using the different libraries. Any advice on how to get around this Cython limitation would be very welcome.
(This answer is just a summary of the comments with a bit more explanation.)
My initial suggestion was to create two extension modules defining a common interface. That way you pick which to import in Python but be able to use them in the same way once imported:
if rendering:
import simGlfw as s
else:
import simEgl as s
s.do_something() # doesn't matter which you imported
It appears from the comments that the two modules also share a large chunk of their code and its really just the library that they're linked with that defines how they behave. Trying to re-use the same sources with
Extension(name='sim1', sources=["sim.pyx",...)
Extension(name='sim2', sources=["sim.pyx",...)
fails. This is because Cython assumes that the module name will be the same as the filename, and so creates a function PyInit_sim (on Python 3 - Python 2 is named slightly differently but the idea is the same). However, when you import sim1.so it looks for the function PyInit_sim1, fails to find it, and gives an error.
An easy way round it is to put the common code in "sim.pxi" and use Cython's largely obsolete include mechanism to textually include that code in sim1.pyx and sim2.pyx
include "sim.pxi"
Although include is generally no longer recommended and cimport is preferred since it provides more "Python-like" behaviour, include is a simple solution to this particular problem.
I'm trying to setup limeJS, the issue is the Internet connection is a problem. I had closure library, box2d, closure compiler and closure templates downloaded separately as .rar files, but I can't find a guide anywhere to set it up like this, everyone just uses(and with reason!!!) the python bin/lime.py init command to get it working. I managed to figure out(yay!) how to setup box2d and closure library but what about the other two?
My laptop is running 64 bits Windows 7. Any help appreciated
All I need is an advice on directory structure, like where to drop the compiler.jar and soy templates .js files, so that when I run the update/create command it doesn't try to download the compiler or templates like it does right now.
I got it working, after taking a quick look at the lime.py file it told me everything I needed, for example both the SoyJs templates file and the compiler need to be in the /path/to/lime/bin/external folder and for example, the lime.py file was expecting a compiler file named compiler-dateOfLatestCompiler.jar instead of compiler.jar.
In general, If you have LimeJS built up in one machine using Python and all, you can just copy paste the whole package anywhere you want and use it just as ususal.
You don't need network once you have all the files/codes for Lime is downloaded.
Infact, you dont even need python for normal development tasks(Python is required to build your js file once you complete development though)
I want to write a program that outputs a list of libraries that I should link to given source code (or object) files (for C or C++ programs).
In *nix, there are useful tools such as sdl-config and llvm-config. But, I want my program to work on Windows, too.
Usage:
get-library-names -l /path/to/lib a.cpp b.cpp c.cpp d.obj
Then, get-library-names would get a list of function names that are invoked from a.cpp, b.cpp, c.cpp, and d.obj. And, it'll search all library files in /path/to/lib directory and list libraries that are needed to link properly.
Is there such tool already written? Is it not trivial to write a such tool?
How do you find what libraries you should link to?
Thanks.
Yeah, you can create a pkg-config file which will allow you to run 'pkg-config --cflags' to get the compiler flags or 'pkg-config --libs' to get the linker libraries.
http://pkg-config.freedesktop.org/wiki/
If you're on Linux, just try looking into /usr/lib/pkgconfig to find some example .pc files that you can use as models. You can still use pkg-config on Windows as well, but it's not something that comes with it.