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.
I have created an .exe from a python app with pyinstaller in Windows. This app opens some matplotlib windows. At first, at the opening of the matplotlib windows, it throwed me the error "This application failed to start because it could not load the Qt platform plugin 'Windows'". I did some digging around and found out that I had to set an enviromental variable 'QT_PLUGIN_PATH' to the value 'C:\Users\user\Miniconda2\Library\plugins'. It worked right but on my PC only. When I open the .exe in other PCs and open the matplotlib windows, it shows me the same error. Is there a way to make it work for every computer?
you need to package QT DLLs with the installer. These DLL's must be shipped with your app because your app has dependency on them. It works on your PC because you have QT packages installed on your machine.
Please follow the link below to see the sample code in order to create package that resolves the DLL issue.
https://github.com/carlosperate/pyinstaller-test/blob/master/package/pyqt5_test.spec
They say, if you can't untie the knot, cut it out. That's what I did because I could not figure out a way, so I completely removed the Qt backend and added a Tk one with this line:
import matplotlib
matplotlib.use('TkAgg')
I'm using python 2.7.9 and encountered a problem when installing pygtk.
It displayed "Runtime error!...R6034 An application has made an attempt to load the C runtime library incorrectly" when installing numpy/scipy after pygtk being installed.
I tried to figure it out by searching it in stackoverflow and found two similar questions: Runtime error R6034 in embedded Python application and An application has made an attempt to load the C runtime library incorrectly.
So following the first one, I deleted the path corresponding to msvcr90.dll, however, it still cannot work. Then I chose to simply delete msvcr90.dll; at this time, this error wasn't presented when installing numpy/scipy, however, these two modules cannot work when simply typing "importing numpy/scipy".
I also renamed gtk-2.0 following the second one. Then numpy and scipy can be successfully installed. But it displayed "Error processing line 3 of C:\Python27\lib\site-packages\pygtk.pth" when installing matplotlib using pip.
I'm really confused about it. Can anybody provide some methods to fix it?
I've installed Python and PyGTK on 5+ machines, at least two of them brand new, clean builds of Win 7.
I've got the An application has made an attempt to load the C runtime library incorrectly error whenever I install a Python package as a windows installer (rather than using pip) on all these machines. It's annoying, but has never made a jot of difference, both Python and Gtk function correctly.
You've deleted msvcr90.dll, and that is why you get your Error processing line 3... If you look at this file, you'll see that line 3 is import runtime, and if you look further into the 'runtime' package, you'll see that this then tries to find the missing dll.
I think your best bet is to try to restore the missing file. If it's still in your recycle bin - great!
If not, the best thing to do is reinstall the Visual C++ runtime library
I made this video to show my way: https://www.youtube.com/watch?v=s6jhR1VBfeU. I use Anaconda to embedded Python in my C++ application. I simply changed "msvcr90.dll" to "msvcr90.dll_hihi" in 3 folders:
C:\Users\your user\Anaconda2\Library\bin, C:\Users\your user\Anaconda2 and C:\Program Files\Intel\iCLS Client (for x64)
So, I'm trying to get gtksourceview python bindings work under windows (I'm developing a cross platform gtk application that shows code, so gtksourceview seemed like a natural choice).
I have pygtk installed and working (I followed the instructions in http://www.pygtk.org/downloads.html)
I tried the instructions in http://projects.gnome.org/gtksourceview/ for gtksourceview.
Here is what I did:
Downloaded and extracted the latest gtksourceview window binaries from: http://ftp.gnome.org/pub/gnome/binaries/win32/gtksourceview/2.10/gtksourceview-2.10.0.zip
The website said gtksourceview needs libxml, so I downloaded and extracted the latest libxml window binaries from:
http://xmlsoft.org/sources/win32/libxml2-2.7.6.win32.zip
Added the folders containing dll files to the PATH (in my computer they were c:\opt\gtksourceview\bin; C:\opt\libxml2-2.7.6.win32\bin)
Installed pygtksourceview with the windows installer:
http://ftp.gnome.org/pub/gnome/binaries/win32/pygtksourceview/2.10/pygtksourceview-2.10.0.win32-py2.6.exe
Renamed the file libxml2.dll to libxml2-2.dll (after running depends on the gtksourceview dll)
Now, the gtksouceview widget seems to work, until I'm trying to set the code's language. When I do that python crashes.
Here is how I crash it in the console (the simplest way i could come up with):
>>>import gtksourceview2
>>>lang = gtksourceview2.language_manager_get_default().get_language('cpp')
>>>lang.get_style_ids()
I'm hoping I'm not the first person to use gtksourceview in python on windows. Any ideas what I should try?
So in case anyone else is wondering -- I grabbed the wrong libxml dll. The right one is in:
http://ftp.gnome.org/pub/GNOME/binaries/win32/dependencies/libxml2_2.7.7-1_win32.zip
I need to keep a large number of Windows XP machines running the same version of python, with an assortment of modules, one of which is python-win32. I thought about installing python on a network drive that is mounted by all the client machines, and just adjust the path on the clients. Python starts up fine from the network, but when importing win32com I get a pop-up error saying:
The procedure entry point ?PyWinObject_AsHANDLE##YAHPAU_object##PAPAXH#Z could not be located in the dynamic link library pywintypes24.dll
after dismissing the message dialog I get in the console:
ImportError: DLL load failed: The specified procedure could not be found.
I searched the python directory for the pywintypes24.dll and it is present in "Lib\site-packages\pywin32_system32" .
What am I missing and is there another way in which I can install Python + Python-Win32 + additional module once and have them running on many machines? I don't have access to the Microsoft systems management tools, so I need to be a bit more low-tech than that.
On every machine you have to basically run following pywin32_postinstall.py -install once. Assuming your python installation on the network is N:\Python26, run following command on every client:
N:\Python26\python.exe N:\Python26\Scripts\pywin32_postinstall.py -install
Another important thing is Good Luck!. The reason is that you might need to do this as admin. In my case such setup worked for all but one computer. I still did not figure out why.
Python (or precisely, the OS) searches the DLLs using os.environ["PATH"] and not by searching sys.path.
So you could start Python using a simple .cmd file instead which adds \server\share\python26 to the path (given the installer (or you) copied the DLLs from \server\share\python26\lib\site-packages\pywin32-system32 to \server\share\python26).
Or, you can add the following code to your scripts before they try to import win32api etc:
# Add Python installation directory to the path,
# because on Windows 7 the pywin32 installer fails to copy
# the required DLLs to the %WINDIR%\System32 directory and
# copies them to the Python installation directory instead.
# Fortunately, in Python it is possible to modify the PATH
# before loading the DLLs.
os.environ["PATH"] = sys.prefix + ";" + os.environ.get("PATH")
import win32gui
import win32con
You could use batch files running at boot to
Mount the network share (net use \\server\share)
Copy the Python and packages installers from the network share to a local folder
Check version of the msi installer against the installed version
If different, uninstall Python and all version dependent packages
Reinstall all packages
This would be pretty much a roll your own central management system for that software.