OSX using swi-prolog pyswip package for python - python

I was trying to execute a third party prolog program for my research. In the meanwhile, I discovered that it requires the pyswip package to execute, due to the program declaration
from pyswip import Prolog
So, after installing this package following the instructions in the INSTALL file, in the root folder of the pyswip installation, the package still could no be found, as with the output error:
ImportError: Could not find the SWI-Prolog library in this platform. If you are sure it is installed, please open an issue.
So after some investigation, I've discovered that the use of the package from python is called from the core.py file, in my case located at
/Library/Python/2.7/site-packages/pyswip
So analyzing this file I could locate the output error text and conclude that the path was not being found according with the specific line
elif platform == "dar": # Help with MacOS is welcome!!
So I noticed too that comment to help with MacOS. Inside the method that tries to found the path properly
(path, swiHome) = _findSwiplDar()
I noticed two array: one with two candidate names of package names and another with the path's candidates. So I've located the first package name "libswipl.dylib" doing a search on my OSX. Finishing, I've added the specific package path to the path array, and everything is working now.
I know this is not the best solution, but I've discovered how things are working and resolved the issue. If someone knows a better way to configure this kind of library without updating the core.py file, I'll be glad to know ;-)
I hope this helps someone!

Related

Anacaonda/Windows 10 - ModuleNotFoundError: No module named 'scipy'

I recently updated Anaconda (Spyder (Python 3.6), Windows 10). Several of my libaries disappeared and had to be re-installed. However, I have been unable to reinstall scipy. When I run "conda install scipy -f" from the Windows PowerShell, scipy seems to be reinstalled. However even if I close Spyder and restat Windows, I continue to get the error: ModuleNotFoundError: No module named 'scipy'.
I know that problems similar to this one have been posted previously, but I have been unable to find anything that seems to fix the problems.
Thanks in advance for any advice (and apologies if this question was posted yesterday as well).
I battled with this same issue. The reason is most likely because you already have a file in the current directory called scipy.py. For example, when I first started with scipy, i made a file literally called scipy.py to practice in. Then, when I tried to import scipy from a different file, the first instance of 'scipy.py' was my practice folder, rather than the actual package which was further into the directory.
I advise you check for folders that you may have named scipy.py that aren't the actual scipy package. I could be wrong, but it seems likely that python will first search the folder it saves your files to, and then trundle over to the packages folder saved elsewhere.
Hopefully this helps some other folks who are stumped by the same issue!

Fatal Python error: initfsencoding: unable to load the file system codec ModuleNotFoundError: No module named 'encodings' [duplicate]

I am attempting to put together a simple c++ test project that uses an embedded python 3.2 interpreter. The project builds fine but Py_Initialize raises a fatal error:
Fatal Python error: Py_Initialize: unable to load the file system codec
LookupError: no codec search functions registered: can't find encoding
Minimal code:
#include <Python.h>
int main (int, char**)
{
Py_Initialize ();
Py_Finalize ();
return 0;
}
The OS is 32bit Vista.
The python version used is a python 3.2 debug build, built from sources using VC++ 10.
The python_d.exe file from the same build runs without any problems.
Could someone explain the problem and how to fix it? My own google-fu fails me.
EDIT 1
After going through the python source code I've found that, as the error says, no codec search functions have been registered. Both codec_register and PyCodec_Register are as they should be. It's just that nowhere in the code are any of these functions called.
I don't really know what this means as I still have no idea when and from where these functions should have been called. The code that raises the error is entirely missing from the source of my other python build (3.1.3).
EDIT 2
Answered my own question below.
Check the PYTHONPATH and PYTHONHOME environment variables and make sure they don't point to Python 2.x.
http://bugs.python.org/issue11288
Parts of this have been mentioned before, but in a nutshell this is what worked for my environment where I have multiple Python installs and my global OS environment set-up to point to a different install than the one I attempt to work with when encountering the problem.
Make sure your (local or global) environment is fully set-up to point to the install you aim to work with, e.g. you have two (or more) installs of, let's say a python27 and python33 (sorry these are windows paths but the following should be valid for equivalent UNIX-style paths just as well, please let me know about anything I'm missing here (probably the DLLs path might differ)):
C:\python27_x86
C:\python33_x64
Now, if you intend to work with your python33 install but your global environment is pointing to python27, make sure you update your environment as such (while PATH and PYTHONHOME may be optional (e.g. if you temporarily work in a local shell)):
PATH="C:\python33_x64;%PATH%"
PYTHONPATH="C:\python33_x64\DLLs;C:\python33_x64\Lib;C:\python33_x64\Lib\site-packages"
PYTHONHOME=C:\python33_x64
Note, that you might need/want to append any other library paths to your PYTHONPATH if required by your development environment, but having your DLLs, Lib and site-packages properly set-up is of prime importance.
Hope this helps.
The core reason is quite simple: Python does not find its modules directory, so it can of course not load encodings, too
Python doc on embedding says "Py_Initialize() calculates the module search path based upon its best guess" ... "In particular, it looks for a directory named lib/pythonX.Y"
Yet, if the modules are installed in (just) lib - relative to the python binary - above guess is wrong.
Although docs says that PYTHONHOME and PYTHONPATH are regarded, we observed that this was not the case; their actual presence or content was completely irrelevant.
The only thing that had an effect was a call to Py_SetPath() with e.g. [path-to]\lib as argument before Py_Initialize().
Sure this is only an option for an embedding scenario where one has direct access and control over the code; with a ready-made solution, special steps may be necessary to solve the issue.
Ran into the same thing trying to install brew's python3 under Mac OS! The issue here is that in Mac OS, homebrew puts the "real" python a whole layer deeper than you think. You would think from the homebrew output that
$ echo $PYTHONHOME
/usr/local/Cellar/python3/3.6.2/
$ echo $PYTHONPATH
/usr/local/Cellar/python3/3.6.2/bin
would be correct, but invoking $PYTHONPATH/python3 immediately crashes with the abort 6 "can't find encodings." This is because although that $PYTHONHOME looks like a complete installation, having a bin, lib etc, it is NOT the actual Python, which is in a Mac OS "Framework". Do this:
PYTHONHOME=/usr/local/Cellar/python3/3.x.y/Frameworks/Python.framework/Versions/3.x
PYTHONPATH=$PYTHONHOME/bin
(substituting version numbers as appropriate) and it will work fine.
From python3k, the startup need the encodings module, which can be found in PYTHONHOME\Lib directory.
In fact, the API Py_Initialize () do the init and import the encodings module.
Make sure PYTHONHOME\Lib is in sys.path and check the encodings module is there.
I had this issue with python 3.5, anaconda 3, windows 7 32 bit. I solved it by moving my pythonX.lib and pythonX.dll files into my working directory and calling
Py_SetPythonHome(L"C:\\Path\\To\\My\\Python\\Installation");
before initialize so that it could find the headers that it needed, where my path was to "...\Anaconda3\". The extra step of calling Py_SetPythonHome was required for me or else I'd end up getting other strange errors where python import files.
I just ran into the exact same problem (same Python version, OS, code, etc).
You just have to copy Python's Lib/ directory in your program's working directory ( on VC it's the directory where the .vcproj is )
There appears to be something going wrong with the release build either failing to include the appropriate codecs or else misidentifying the codec to use for system APIs. Since the python_d executable is working, what does that return for os.getfsencoding()? (Use the C API to call that between your Initialize/Finalize calls)
I had the same issue and found this question. However from the answers here I was not able to solve my problem. I started debugging the cpython code and thought that I might be discovered a bug. Therefore I opened a issue on the python issue tracker.
My mistake was that I did not understand that Py_SetPath clears all inferred paths.
So one needs to set all paths when calling this function.
Link to the issue conversation
For completion I also copied the most important part of the conversation below.
My original issue text
I compiled the source of CPython 3.7.3 myself on Windows with Visual Studio 2017 together with some packages like e.g numpy. When I start the Python Interpreter I am able to import and use numpy. However when I am running the same script via the C-API I get an ModuleNotFoundError.
So the first thing I did, was to check if numpy is in my site-packages directory and indeed there is a folder named numpy-1.16.2-py3.7-win-amd64.egg. (Makes sense because the python interpreter can find numpy)
The next thing I did was to get some information about the sys.path variable created when running the script via the C-API.
#### sys.path content ####
C:\Work\build\product\python37.zip
C:\Work\build\product\DLLs
C:\Work\build\product\lib
C:\PROGRAM FILES (X86)\MICROSOFT VISUAL STUDIO\2017\PROFESSIONAL\COMMON7\IDE\EXTENSIONS\TESTPLATFORM
C:\Users\rvq\AppData\Roaming\Python\Python37\site-packages
Examining the content of sys.path I noticed two things.
C:\Work\build\product\python37.zip has the correct path 'C:\Work\build\product\'. There was just no zip file. All my files and directory were unpacked. So I zipped the files to an archive named python37.zip and this resolved the import error.
C:\Users\rvq\AppData\Roaming\Python\Python37\site-packages is wrong it should be C:\Work\build\product\Lib\site-packages but I dont know how this wrong path is created.
The next thing I tried was to use Py_SetPath(L"C:/Work/build/product/Lib/site-packages") before calling Py_Initialize(). This led to
Fatal Python Error 'unable to load the file system encoding'
ModuleNotFoundError: No module named 'encodings'
I created a minimal c++ project with exact these two calls and started to debug Cpython.
int main()
{
Py_SetPath(L"C:/Work/build/product/Lib/site-packages");
Py_Initialize();
}
I tracked the call of Py_Initialize() down to the call of
static int
zipimport_zipimporter___init___impl(ZipImporter *self, PyObject *path)
inside of zipimport.c
The comment above this function states the following:
Create a new zipimporter instance. 'archivepath' must be a path-like
object to a zipfile, or to a specific path inside a zipfile. For
example, it can be '/tmp/myimport.zip', or
'/tmp/myimport.zip/mydirectory', if mydirectory is a valid directory
inside the archive. 'ZipImportError' is raised if 'archivepath'
doesn't point to a valid Zip archive. The 'archive' attribute of the
zipimporter object contains the name of the zipfile targeted.
So for me it seems that the C-API expects the path set with Py_SetPath to be a path to a zipfile. Is this expected behaviour or is it a bug?
If it is not a bug is there a way to changes this so that it can also detect directories?
PS: The ModuleNotFoundError did not occur for me when using Python 3.5.2+, which was the version I used in my project before. I also checked if I had set any PYTHONHOME or PYTHONPATH environment variables but I did not see one of them on my system.
Answer
This is probably a documentation failure more than anything else. We're in the middle of redesigning initialization though, so it's good timing to contribute this feedback.
The short answer is that you need to make sure Python can find the Lib/encodings directory, typically by putting the standard library in sys.path. Py_SetPath clears all inferred paths, so you need to specify all the places Python should look. (The rules for where Python looks automatically are complicated and vary by platform, which is something I'm keen to fix.)
Paths that don't exist are okay, and that's the zip file. You can choose to put the stdlib into a zip, and it will be found automatically if you name it the default path, but you can also leave it unzipped and reference the directory.
A full walk through on embedding is more than I'm prepared to type on my phone. Hopefully that's enough to get you going for now.
I had the problem and was tinkering with different solutions mentioned here. Since I was running my project from Visual Studio, apparently, I needed to set the environment path inside Visual Studio and not the system path.
Adding a simple PYTHONHOME=PATH\TO\PYTHON\DIR in the project solution\properties\environment solved the problem.
For me this happened when I updated Python 64 bit from 3.6.4 to 3.6.5. It threw some error like "unable to extract python.dll. Do you have permissions."
Pycharm also failed to load interpreter, even though I reloaded it in settings. Running python command gave same error, with and without administrator mode.
Reason
There was error in installation of Python, include folder in python installation directory C:\Users\USERNAME\AppData\Local\Programs\Python\Python36 was missing
Reinstalling Python also dint solve the issue.(Not removal and install)
Solution
Uninstall Python and Install of Python again.
Because running installer was just extracting same files excluding include folder
In my cases, for windows, if you have multiple python versions installed, if PYTHONPATH is pointing to one version the other ones didn't work. I found that if you just remove PYTHONPATH, they all work fine
For those working in Visual Studio simply add the include, Lib and libs directories to the Include Directories and Library Directories under
Projects Properties -> Configuration Properties > VC++ Directories :
For example I have Anaconda3 on my system and working with Visual Studio 2015 This is how the settings looks like (note the Include and Library directories) :
Edit:
As also pointed out by bossi setting PYTHONPATH in your user Environment Variables section seems necessary.
a sample input can be like this (in my case):
C:\Users\Master\Anaconda3\Lib;C:\Users\Master\Anaconda3\libs;C:\Users\Master\Anaconda3\Lib\site-packages;C:\Users\Master\Anaconda3\DLLs
is necessary it seems.
Also, you need to restart Visual Studio after you set up the PYTHONPATH in your user Environment Variables for the changes to take effect.
Also note that :
Make sure the PYTHONHOME environment variable is set to the Python
interpreter you want to use. The C++ projects in Visual Studio rely on
this variable to locate files such as python.h, which are used when
creating a Python extension.
So, for some reason the python dll fails to locate the encodings module. The python.exe executable apparently finds it because it has the expected relative path. Modifying the search path works.
The reason for all of this? Don't know but at least it works. I highly suspect a typo on my part somewhere, that's usually the reason for odd bugs it seems.

No module named 'meshpy._triangle'

I installed meshpy (using python 2.7) following the instructions here on my ubuntu 16.04 LTS and trying to run examples from here after browsing into the directory of meshpy. Part of the example that I'm trying to run is below:
from __future__ import division
from __future__ import absolute_import
import meshpy.triangle as triangle
but I keep getting error No module named meshpy._triangle
Does anyone have a hint of what I might be missing ?
Likely you have created file named meshpy within your python package, which leads to the module shadowing, renaming your file shall fix the problem.
See more by next links:
The name shadowing trap
Python: Problem with local modules shadowing global modules
After an entire day of labor I realized the python packages that I had were not correct and causing conflicts. To begin with here is the link to the installation documentation of meshpy which I followed Here is a pointwise summary of what I realized caused problem
Step 1 says download the file, unzip it using the command given in the doc, and browse to the directory 'MeshPy-XXXXX', where 'XXXXX' refers to the version.
The issue in this step is that a file called CMakeList.txt is missing in this directory and while configuring in step 2 the system complains about the missing file.
The solution is to download the git version instead of the direct download as mentioned in the second part of step1 or manually copy the file CMakeList.txt into the MeshPy-XXXXX directory. I chose the latter solution.
In step 2 asks us to browse to the directory and issue the command ./configure on the terminal. This didn't work for me. The directory contains a script called configure.py . Hence instead I issued python3.5 configure.py
If you issue python configure.py and python calling python2.7 then you should make sure python2.7 has matplotlib, numpy installed as meshpy depends on these packages
The last of step2 where you need to issue command python setup.py install is a tricky part where things went crazy for me. Firstly, I issued python setup.py but what I should have done is issuing python3.5 setup.py (or better creating an alias to python3.5 in bash).
When I pinned down the mistake, I started getting another error both with python2.7 and python3.5, last three lines of which looks like below :
bpl-subset/bpl_subset/boost/python/detail/wrap_python.hpp:50:23: fatal error: pyconfig.h: No such file or directory
compilation terminated.
error: command 'x86_64-linux-gnu-gcc' failed with exit status 1
When I looked up stackoverflow for possible similar errors, I came across this article and used the second solution in the post and installed python2.7-dev/python3.5-dev which solved the problem .
Go to the installation page and click on 'Download MeshPy' link. Click on 'Download Files'. Download the tar file. Unzip it. Then copy the 'meshpy' folder and paste it inside your python lib directory where other packages are stored. Hope it will solve the problem.

Trouble with failing to build _tkinter after installing binary tcltk

I am running linux and python 2.7.14 I have successfully installed the binary version of tcltk. I installed it into the same directory as python27 such that the following directories were all added in the same folders, namely: include, lib, etc. The bits were not all found when I configured python again so when I checked the setup.py file it mentioned I could do the following, which I did:
make clean
./configure --with-tcltk-includes="-I/home2/bishopk2/python27/include" --
with-tcltk-libs="-L/home2/bishopk2/python27/lib/tcllib1.18 -ltclm.n -L/
home2/bishopk2/python27/lib/tklib0.6 -ltkm.n"
make TCLTK_INCLUDES="/home2/bishopk2/python27/include"
TCLTK_LIBS="/home2/bishopk2/python27/lib"
I have tried all permutations of this (i.e., with and without the tcllib1.18, ltclm.n, etc., etc.)
I am not sure the best way to share a config.log on stack overflow but here is a link:
https://www.pharmacoengineering.com/share-a-file/
(I made the pdf downloadable)
I had to save it as a pdf file so that it would upload to wordpress.
When I looked at it, I am not sure why the tcl.h file could not be found because when I:
find . -name "tcl.h"
It says that it is in my /home2/bishopk2/python27/include folder.
All of the libraries are there and it should be able to connect Tkinter with my tcl and tk libraries.
Any help would be greatly appreciated.
Best wishes,
Corey
tcllib and tklib and libraries of Tcl scripts.
To build tkinter you need to link to the binary shared object library (a .so file). This should be named libtcl8.6.so or something similar. It is not clear from your post that you realize tclM.N is a way of saying Major number, Minor number but you should put the numbers in for your installed version. So on my Debian based system I will provide --with-tcltk-includes=/usr/include/tcl8.6 --with-tcltk-libs=/usr/lib/x86_64-linux-gnu given your example. If you need to put in the library name then -ltk8.6 -ltcl8.6 (the linker drops the lib prefix from the filename.

Undefined variable from import when using vtk

I am coding in python 2.7 using python-vtk 6.2.0 installed with the Ubuntu package manager.
I use eclipse + pydev as IDE and I can run the code successfully in shell and from within eclipse.
The only annoying problem I have is that the code analyser keeps posting errors of the type: Undefined variable from import: vtkxxxxxx whenever I do
import vtk
vtk.vtkTransformPolyDataFilter
vtk.vtkActor
vtk.vtkWhatever
I tried to reset the interpreter and I have also tried to manually add the library .so files to the PYTHONPATH, with no luck.
Also I can see the the vtk package in the project tree under system libs and I have no errors on the line import vtk
Is there a particular unusual way to include vtk library in pydev? Am I doing something stupid I do not see?
Thank you all!
I have found a similar question already asked about numpy. It has been solved so maybe you might find your answer in there. The URL for the issue is https://stackoverflow.com/a/14082269/7171962
Btw. This may be of no help to you.
I hope this helps.
had you gone through this link enter link description here
Hope this will help

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