Develop Reference

Python Perforce module Error: No module named 'P4'

I got the P4 python module for win10 via the installer on their page: https://www.perforce.com/downloads/helix-core-api-python
Its for python 3.9, though I have tested it with both Python 3.10 and 3.9 and it always throws the error: No module named 'P4' when I try to use it inside visual code.
Interpreter is set up correctly (tried 310 and 39).
Im a bit lost here and would love some help.
The installer package installed the following files into site-packages:
P4.py
P4API.cp39-win_amd64.pyd
and a folder with 4 metadata files in it
P4.py on itself looks good, no errors.
Edit: Im trying to use it with Blender. Currently shipped python version within that is 3.10.2. Also tried a older blender version which uses 3.9.7.
Both wont work.

Visual studio code is known for it's bugs with python. You could try using "PyCharm". Make sure to install the modules from Pycharm's settings instead of terminal.
(I'm not sure if this is the reason, but it's worth the try. Had the same issue and the mentioned way solved it.)

Windows Forms in Visual Studio with Python

Steps to reproduce:
I created a new project in Visual Studio
Selected Python > Desktop > "IronPython Windows Forms Application"
However, as soon as I open the project I encountered several errors which I don't know how to solve. The errors are unresolved import clr an similar.

If you're getting the following error unable to resolve 'clr':
It's likely that you don't have a python interpreter installed or configured for Visual Studio
Per the question The environment ironpython 2.7-32 appears to be incorrectly configured or missing
The Visual Studio Installer does not include an IronPython Package option to install
So you need to:
Download IronPython from Github and install it
Then, select the correct Python environment within your VS project.

Python IDLE not opening due to Tcl/tk error

I have just installed the latest version of Python 3.6.5 from python.org. I am using 64 bit Windows 8.1 .Earlier it was showing all kinds of .DLL errors, I tried installing all the updates and C++ Redistributable but nothing happened, then I manually downloaded all different DLL's and pasted them in the System-32 folder. By doing that the python command shell did start working but as soon as I try to open the IDLE, nothing happens, no error message is shown and nothing pops up on the monitor.
I read a lot of answers on the net and when I tried writing "import tkinter" in the python command shell it shows that the module not found and this message also - " import _tkinter # If this fails your python may not be configured for Tk" .
Please resolve this issue.

If you did not have the C runtime (CRT...) .dll MS Visual C++ applications compiled with VS2015 or VS2017, including Python since 3.5, it is very likely because you turned off automatic Windows updates. If you got interactive Python working, you must have gotten the right one installed.
If _tkinter is not installed, it must be because the box for optionally installing tcl/tk, _tkinter, tkinter, and IDLE was not checked when you said 'install'. If you still have the installation file where it was when you ran it, you can go to the Control Panel installed programs dialog, click on 3.6.5, and ask to 'Repair'. You should be able to add the needed checkmark. Otherwise rerun or redownload the file from python.org.
If you need further help with installation questions, the python.org python-list is sometimes a better forum.

Python on Windows - compiling

Like many before me I don´t succeed in installing a few Python packages (mysql, pycld2, etc.) on Windows. I have a Windows 8 machine, 64-bit, and Python 3.4. At first I got the well-known error "can´t find vcvarsall.bat - install VS C++ 10.0". This I tried to solve by installing MinGW and use that as compiler. This did not work. Then finally I found an installer for this VS C++ 10.0 here http://microsoft-visual-cpp-express.soft32.com/free-download/. This doesn´t work too good either. Now it seems to find the vcvarsall file but instead gives me a couple of new errors
nclude -IC:\Python34\include /Tc_mysql.c /Fobuild\temp.win32-3.4\Release\_mysql.
obj /Zl_mysql.c_mysql.c(42) : fatal error C1083: Cannot open include file: 'config-win.h':
No such file or directory
error: command 'C:\\Program Files (x86)\\Microsoft Visual Studio 10.0\\VC\\BIN\\cl.exe' failed with exit status 2
And:
pycldmodule.cc
bindings\pycldmodule.cc(16) : fatal error C1083: Cannot open include file: '
strings.h': No such file or directory
error: command 'C:\\Program Files (x86)\\Microsoft Visual Studio 10.0\\VC\\BIN\\cl.exe' failed with exit status 2
So now it doesn´t find strings.h and config-win.h and I´m too new to these sorts of problems to know what to look for. Anyone knows what I should do?
The thing is that I could just not use Windows and go over to Ubuntu as, for what I´ve understood, works painlessly with python. However, I have to use the win32com package which doesn´t exist on Ubuntu (have I understood that right?).
If I can´t solve these installing hassles on Windows, would a solution be to use a Windows virtual machine for the win32com part and do the rest on a host Ubuntu (or the other way around)? Would there be anyway to communicate between the two in that case? I.e. sending strings or arrays of data.

I have faced the exact same issues for Python 2.7 on 64 bit Windows trying to install pycld2.
Tried many methods like installing VS express 2008, MingW, etc and it just doesnt work.
What saved me is this link:
https://github.com/aboSamoor/polyglot/issues/11
The proposed solution is to download the binaries from http://www.lfd.uci.edu/~gohlke/pythonlibs/ and pip install .whl
The cpXX denotes the version of python. So in my case, I used cp27.
Hope it helps

I would recommend installing Ubuntu (as a Ubuntu user), you can dual-boot. However, that isn't an answer.
MySQLClient (the fork for Python3) is available a precompiled binary from here:
http://www.lfd.uci.edu/~gohlke/pythonlibs/#mysqlclient
Try to find precompiled binaries for simplicity sake. As far as troubleshooting the install goes, I've tried the recommend VC Studio 9.0 on fresh installs and it cannot find stdint.h (which, like yours, suggests it's more than broken).

You could try http://www.activestate.com/activepython/downloads for Windows. I t includes compiled binaries, avoiding the need for a C complier.

I grew frustrated with trying to get python and other packages to compile/play nicely on Windows as well. Switching over to Ubuntu was a breath of fresh air, for sure.
The win32com package is made specifically for Windows hosts, so that could not longer be used, but there are other ways to achieve the same thing in Ubuntu.
Are you trying to target Windows specifically? What are you using win32com for?

Looks like you're missing MySQL dev package. Another StackOverflow question has the details. But if I were you, I'd go the route Alexander Huszagh recommended and get my precompiled binaries from http://www.lfd.uci.edu/~gohlke/pythonlibs/#mysqlclient

PyQt 4.7 - ImportError after installing on Windows

I've been trying to install PyQt 4.7 on Vista, but I am getting an ImportError when I try to do: from PyQt4 import QtCore, QtGui.
ImportError: DLL load failed: The specified module could not be found.
I've checked my System Path, and C:\Python31\Lib\site-packages\PyQt4\bin is on there.
I can't run any of the examples, but the Designer, Assistant and Linguist run fine.
I am using ActivePython 3.1, if that makes any difference. And I haven't had any previous version of PyQt installed.
Edit:
I've copied the QtCore4 and GtGui4 dlls to C:\Python31\Lib\site-packages\PyQt4. That fixes some of the examples, but I still can't use the example browser.

Are you sure there is a \bin directory for your version of PyQt?
I am running PyQt 4.4, and all my binaries are right in:
C:\Python31\Lib\site-packages\PyQt4
Which is what I have my path pointing too.
It sounds like PyQt4 was installed improperly... did you run this?
python setup.py install
There shouldn't be a bin there...

Just wanted to chime in that I had the same problem on a WinXP install of:
python 2.7
Qt 4.7.1 (10.05)
PyQt 4.8.1
I used the windows installer version of all 3 of those items.
Copying the contents of the C:\Python27\Lib\site-packages\PyQt4\bin folder up to the main PyQt folder (C:\Python27\Lib\site-packages\PyQt4) stopped the 'dll not found' errors that python was throwing.

Also chiming in. I installed both python 2.6 and PyQt 4.8.3 on a Windows 7 machine using the windows installers (I did NOT run 'python setup.py install').
I tried to run spyder (which requires PyQt 4.4 or greater) and failed because it couldn't find the PyQt .dlls. I copied all the .dlls from the \Lib\site-packages\PyQt4\bin folder to the \Lib\site-packages\PyQt4 folder, and spyder launches just fine.

PyQt installation also depends on the version of python installed on your platform.Python3.+ is incompatible with Python version < 3.x.
I was facing the same problem as I have Python 2.7 installed on my machine but I downloaded the latest binary which was PyQt-Py3.2-x86-gpl-4.9.exe. If you see here the binary has python version also mentioned in name after PyQt which is Py3.2. I uninstalled PyQt and installed PyQt-Py2.7-x86-gpl-4.9.exe which points to Python 2.7 and it fixed the problem.
Probably they could have mentioned the naming convention online or in some documentation to be more simpler.

I had the same problem. I got my program running from within Eclipse but when I tried running it directly from the command line I still got the same error.
I solved it by renaming the C:\Users\Me\AppData\Roaming\Python\Python27\site-packages\PyQt4 directory. (I'm guessing leftovers from a previous PyQt install)
I am using ActivePython.

I think there are at least two possible error conditions
1. ImportError: DLL load failed: The specified module could not be found.
then you have to check your PyQT version is comptible with your python. In other words, if you use python 3.3, then you can only use PyQT for python3.3 and python 3.3 will not work with PyQT for python3.4
This was the problem I met. I solved it with re-install it
2. Import Error: DLL load failed: %1 then something strange on a different encoding Win32.
then it would be a OS problem. If you use 32bit Python then you have to use 32bit PyQt, so do 64bit

Here's how I could fix those errors on Windows 7:
Get the PyQt4 wheel from
http://www.lfd.uci.edu/~gohlke/pythonlibs/#pyqt4.
Make sure that the version is exactly the same as your Python version (i.e. Python 3.3 doesn't work with PyQT for Python 3.4). Also make sure to download the 64bit version if you are on a 64bit machine and vice versa.
Extract the wheel with 7zip
Rename the PyQt4-4.11.4.data (or similar) directory to PyQt4
Go to PyQt4\purelib\PyQt4\ and move everything to the root PyQt4 folder. You can delete the purelib folder now
Copy the whole PyQt4 folder to your Python interpreters 'site-packages' folder (e.g. C:\Python34\Lib\site-packages)
Go to PyQt4\data\Lib\site-packages and move all the files to C:\Python34\Lib\site-packages\

In my case I needed MSVCP140.dll. I have solved this problem by dowloading Visual C++ Redistributable for Visual Studio 2015:
https://www.microsoft.com/en-us/download/details.aspx?id=48145
Got this solution from MSVCP140.dll missing
I am using Pyqt4 and Python 3.6 in Windows7.