I need to create an OpenGL context in Tkinker, for using it with PyOpenGL Python module.
Tkinker doesn't natively support OpenGL context, but I found this page on PyOpenGL docs, explaining how to use a wrapper included in the module for this:
http://pyopengl.sourceforge.net/documentation/context/
I tried to run the provided code but I got a message saying TOGL module was not found.
I downloaded the module from http://togl.sourceforge.net/, but couldn't get it to work.
PS. I did the test on Mac OS X, with Python 3.2, using virtualenv.
PyOpenGL provides Python bindings for the Tk OpenGL widget (Togl) but not Togl itself, that is why you had to download it. Now, to install Togl is easy but there isn't a tool ready to perform the task. Since the Python bindings will use Tcl to load the Togl module, the widget needs to live in one of the directories present in Tcl's auto_path, which is where Tcl looks for loading libraries. What you can do is start a Tcl interpreter, tclsh, and check which are these directories by doing puts $auto_path. In my case I copied the directory lib/Togl2.0 (inside the Togl's .tar.gz) to /opt/local/lib/tcl8.5. You can also extend auto_path to look for other directories, but I'm not covering that here.
Then I tested using Python 2.7 on Mac OSX. Doing import OpenGL.Tk tries to load Togl, too bad it fails. The reason is that Togl comes precompiled for i386, since I built Python as a universal binary all I did was run it as arch -i386 python2.7, and now import OpenGL.Tk works.
Related
Python version: 3.8.1
Spyder version: 3.3.6
Qt version: 5.12.9
Wrapper: develop using PyBind11
I am wrapping a dll develop in C++ which use Qt dlls to be used with Python. I wrote the wrapper with Visual Studio 2019 using the compiler MSVC (as my dll is compiled with MSVC). After generating the solution in VS2019 I obtain a .pyd file which can be import with python.
It works good when I use python on line command:
Start cmd.exe
$python
import MyLibName
I can use the functions/classes ...
But if I try with Spyder, I get the following error:
ImportError: DLL load failed while importing PyStack: The specified module could not be found..
So here are my questions :
Is there a way to get more information about ImportError like the name of the missing dll or something?
I don't understand why the issue only happen with spyder. I tried with IPython Qt Console and it work. Does spyder use a embeded python version or something ?
I don't fully understand how dll shall be managed, I mean shall I provide dll like libGLESV2.dll with the .pyd or just give a path where to find it ?
Thank you in advance.
My guess
I think I find out which part of Qt/python is producing this issue, but I still don't know how to solve it.
My dll use signals/slots which need an event loop to be performed. If an event loop is already running the dll will try to use it, if the loop version (ex : PyQt5==5.14.1) isn’t the same as mine (ex Qt==5.15.1) import will be impossible.
Note that the reverse is true, if I run my dll an then try to start a loop with %gui qt the command will throw an error.
How to reproduce the issue :
Compile a Qt project available here.
Copy the output dll in the folder PyMyStack/dependencies of the VS Project (available here)
Compile the VS project.
Open an IPython console (without using qt has event loop)
Import the module created with VS (Import PyMyStack)
Run the magic command %gui qt
Last command shall print : ERROR:root:DLL load failed while importing QtSvg: The specified procedure could not be found.
How to hide/solve the problem:
Disclaimer : The solutions presented here are surely not the best, if you know a better one please share it ☺
If you just want to import your lib in Spyder, you can use another event loop. Here are the steps to change this:
In Spyder menus go to Tools→Preferences
Select “IPython console”
Go to “Graphics” tab and change the backend combo box to any other values than Qt or Automatic
If you want to use Qt event loop you will have to update it. You can do this with pip command, but remember than Spyder is not compatible with some version. Here is the pip command:
Pip install PyQt5==X.Y.Z
Where X and Y are the same version use to compile your Qt project. The last digit version seems to not be important.
I have been coding in python for about 2 months, but I'm only familiar with basic object-oriented programming, so I do not really understand things like how searching for modules is implemented. (Basically I'm a noob.)
I pip installed a package called Opentrons Opentrons 2.5.2 and all its dependencies into the samefolder as a python script I'm currently writing. However when I tried to import the module below[1], I get an error saying that "Opentrons is not a module". Then, I tried shifting it into the python library because I found out the search path using the pprint module and it seems to work. I was wondering if I can specify the search path from the .py file itself instead of manually printing the search path and putting the file into the library that the script searches for. (Willing to put in images of the directories I put the opentrons package in if it helps.)
[1]
import sys
import pprint
pprint.pprint(search.path)
from opentrons import robot, containers, instruments
Edit: I realise that the fact that I am running all my scripts in a Spyder console located in a python 3.6 environment might be important.
You can try using the __import__ function, or importlib. This should allow you to specify the path.
I was trying to do gui programming in Python.I figured out that PySide is a good framework to start with.As i was running Python 2.7.2 i downloaded PySide 2.7 and tried running a sample app.I got QtCore Library not loaded error.
This is the error that i got..
from PySide import QtCore, QtGui
ImportError: dlopen(/Library/Python/2.7/site-packages/PySide/QtCore.so, 2):
Library not loaded: QtCore.framework/Versions/4/QtCore
Referenced from: /Library/Python/2.7/site-packages/PySide/QtCore.so
Reason: image not found
I googled and found out that many people were facing the same issue and i saw solutions being posted based on exporting DYLD_FRAMEWORK_PATH. I was not able to follow this.
Could anyone please tell me whats the issue and how to fix it!!
Thanks..
You don't mention the OS you are working on, but from the paths in your error message it looks like you're on Mac OSX.
I'm not an expert in PySide at all, but I had the same problem a while ago and I think I know what's going on: The library at /Library/Python/2.7/site-packages/PySide/QtCore.so is the part that makes the Qt Core C++ library available to Python. It is just the wrapper though or some sort of translator between C++ and Python, the actual C++ functionality is elsewhere - and when the Python interpreter tries to load the C++ library that contains that functionality from QtCore.framework/Versions/4/QtCore, if fails to find it, hence the error message.
A quick and dirty way to solve your problem is to create symbolic links from the location where QtCore.so expects the C++ library to where it actually is. For that, you will obviously have to find the C++ library. If you downloaded Qt 4.8.4 as an installer from the Qt Project page, the libraries AFAIK are somewhere in /usr/lib, so you would create a symlink like this:
ln -vis /usr/lib/<insert subfolder>/QtCore.framework /Library/Python/2.7/site-packages/PySide/QtCore.framework
You will have to do this in a similar way for QtGui and any other Qt library you want to use as well. Note that this obviously does not symlink the library itself, but the folder in which QtCore.so expects it.
An alternate way would be to build PySide from the sources (which is what I ended up doing), but that takes longer - and you sound like you just want to get going with Python and Qt.
Have you installed standalone QT package for mac?
Qt for Mac OS X: Download Qt 4.7.4 ftp://ftp.qt-project.org/qt/source/qt-mac-opensource-4.7.4.dmg standalone pyside installation raises same error log for me
I'm using Mountain Lion at the moment.
I've installed Blender (because it's a dependency of OpenGrasp), and downloaded OpenGrasp. However, I try to load the robot editor up and I get this:
$ python GraspRobotEditor.py
Traceback (most recent call last):
File "GraspRobotEditor.py", line 34, in <module>
import Blender
ImportError: No module named Blender
How do I point Python to the Blender python interface? the Getting Started guide doesn't instruct you much here.
(I'm sure this is a trivial problem to solve but I'd like to see this documented on StackOverflow anyway.)
From the error you it can't find the python module Blender which represents the python hook to Blender. So there could be a few This could be any number of reasons to do with your setup.
The first is that the Blender module is runtime generated whileBlender is running. The specific 'Blender' module used is part of the Blender 2.4x series. According to the link you provided there, they mention porting to newer versions but checking their snv the code is definitely written for 2.49.
Blender 2.49b was the last stable release - http://download.blender.org/release/ Ensure you are using that.
The next thing is whether it can be run via the the Run Script command
TL:DR
Start up blender
Switch to the text workspace
Open the script and see if it can be run directly.
If not you will need to install the folder to the Blender modules directory of your install and then try running it.
Edit: Was looking at into the SVN some more and there does appear to be a version 2 for blender 2.5+ which can be put into a zip file and installed via the add-on installer. According to the bl_info it was build for 2.58 but what support level you would need to try out yourself.
I am using python 2.6.5 on an Ubuntu intalled server.
I need to integrate an API for our applicaion, in that case, i needed to use a DLL given to me by the API provider. Their example of code about api integration is written in Visual Basic... I made a search on google and found some examples of using ctypes , and i try using cdll and pydll, which caused the following error...
OSError: /home//some.dll: invalid ELF header
One possibility is using IronPython, but i do not have much information about ironpython so i am not sure if it will handle my needs completely..
Is there any available module that let me use that dll on python (or aynthing that i am missing from the exixting ones). It is hard to upgrade my python version?
DLLs may be windows creatures, but if a DLL is 'pure .NET' and doesn't utilize executables specific to windows etc., then it can work often in Linux, through Mono. (mono ipy.exe).
Ironpython's System and similiar windows modules are customized to be os agnostic (to a untested degree).
I have successfully run NHibernate, FluentNHibernate, log4net, and a few other commonly used DLLS in Ubuntu.
import clr
import sys
sys.path.append(os.path.abspath('./DLL')) #where your dlls are
clr.AddReference('System')
clr.AddReference('FluentNHibernate')
from FluentNHibernate.Cfg.Db import PostgreSQLConfiguration
The key seems to be to import DLLs in this fashion. If a dll imports another (fluentnhibernate imports nhibernate), you don't need to import Nhibernate for example.
DLLs are Windows creatures. The only way you'll be able to use a DLL is by using a Windows build of Python. You'll be able to run Windows Python on Ubuntu by having Windows installed inside a virtual machine. You also might be able to run it using Wine.
An alternative, of course, is to ask your API provider if they have a Linux version of the API.
First, check if your DLL is a .NET Assembly file. An "Assembly DLL file" has nothing to do with the assembler. It's simply a way the .NET framework stores its bytecode inside a DLL file!
Do file library.dll in Linux. If it says something like this:
PE32 executable (DLL) (console) Intel 80386 Mono/.Net assembly, for MS Windows
then you're lucky: it's an assembly file. You can run it on Linux.
Install Mono. Install Python.NET. Forget IronPython: it's dead.
Now, in Python.NET, you can do this:
import clr
clr.AddReference('./library.dll')
# the library has just registered a namespace we can use
from LibraryName import *
but how do you know what to import?
Auto-complete.
Or use monop tool to inspect the DLL like this:
$ monop -r library.dll
Assembly Information:
LibraryName
Version=9.9.3.0
Culture=neutral
PublicKeyToken=null
LibraryName.ClassName
...
$ monop -r library.dll LibraryName.ClassName
public class ClassName {
public ClassName (string inputString);
...
}
and it will tell you everything about that library