Develop Reference

"jupyter-kernelspec" not found while installing iqsharp however it exists on PATH

While installing QDK for use with python as described in this guide, on executing dotnet iqsharp install I get the following exception
Traceback (most recent call last):
File "c:\users\hp\appdata\local\programs\python\python36\lib\runpy.py", line 193, in _run_module_as_main
"__main__", mod_spec)
File "c:\users\hp\appdata\local\programs\python\python36\lib\runpy.py", line 85, in _run_code
exec(code, run_globals)
File "C:\Users\hp\AppData\Local\Programs\Python\Python36\Scripts\jupyter.exe\__main__.py", line 7, in <module>
File "c:\users\hp\appdata\local\programs\python\python36\lib\site-packages\jupyter_core\command.py", line 247, in main
command = _jupyter_abspath(subcommand)
File "c:\users\hp\appdata\local\programs\python\python36\lib\site-packages\jupyter_core\command.py", line 134, in _jupyter_abspath
'Jupyter command `{}` not found.'.format(jupyter_subcommand)
Exception: Jupyter command `jupyter-kernelspec` not found.
However, when I run jupyter-kernelspec command on cmd it is found on PATH. Why is it happening that python is unable to locate a command if cmd can find it?

To address your specific question, you can see whether Python can locate jupyter-kernelspec (and if so, where) by running something like:
python -c "from shutil import which; print(which('jupyter-kernelspec'))"
But as to the underlying cause of the error, it seems likely that your Jupyter installation is incomplete and/or your environment is somehow misconfigured. You may want to try creating a new Python environment (perhaps using Anaconda, if you're new to Python development) and then following the QDK installation instructions again from inside that new environment (e.g., from an Anaconda command prompt with the new environment active).
Edit: From comments below, it sounds like the problem is that you have a trailing semicolon in your PATHEXT environment variable. This confuses shutil.which(), and this in turn prevents Jupyter from finding the necessary executable. (I can reproduce this problem locally by adding a trailing semicolon to PATHEXT.)
The fix should be simply to remove the trailing semicolon from PATHEXT.

Error installing pyflycapture2 on Windows

I am attempting to install this https://github.com/jordens/pyflycapture2 python binding on my Windows machine. The readme only has instructions on how to do it for Linux systems, but I imagine the library should still work.
I am able to run "python setup.py install" and it seems to successfully complete, but when I try to run "python test_flycapture2.py" I get this error:
C:\Users\clinic\Desktop\pyflycapture2>python test_flycapture2.py Traceback (most recent call last):
File "test_flycapture2.py", line 20, in <module>
import flycapture2 as fc2
File "build\bdist.win-amd64\egg\flycapture2.py", line 7, in <module>
File "build\bdist.win-amd64\egg\flycapture2.py", line 6, in __bootstrap__
ImportError: DLL load failed: The specified module could not be found.
This seems to imply that flycapture2 wasn't installed correctly. When I instead just open a python session and do "import flycapture2" I get the following error:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "build\bdist.win-amd64\egg\flycapture2.py", line 7, in <module>
File "build\bdist.win-amd64\egg\flycapture2.py", line 6, in __bootstrap__
ImportError: DLL load failed: The specified module could not be found.
Have I done something wrong with the installation process or does pyflycapture2 just not work with Windows?

A dumb solution that's worth a try. There are chances that the DLL are searched directly from where you're starting the python script. So if you have the dll somewhere on your computer, copy it along where you have your test_flycapture2.py.
But given the fact that the setup.py file has a whole bunch of absolute paths in there, I would not place my hopes too high. You can also try to install FlyCapture 2 at the exact same path, run python setup.py bdist_wheel (you will need to install wheel first with pip) in the pyflycapture2 folder, and see if that succeeds.
If it does, try installing the generated wheel (that will be in dist/ subfolder) by doing pip install dist/pyfly....wheel and test again.
Hope this helps

I'm answering this mostly because I found another post where the same question had been posted but the original problem was never answered.
How do I run an installed Python module on Windows?
In the comments, the original poster says that it suddenly started working. I found that the solution was simply to restart my computer. I have now attempted this on two computers and this worked for both of them.

Pydot error: file format "png" not recognized

I need to build a pythonic graph solution through pydot and when tried to run a simple code like:
import pydot
graph = pydot.Dot(graph_type='graph')
i=1
edge = pydot.Edge("A", "B%d" % i)
graph.add_edge(edge)
graph.write_png('graph.png')
Which is designed to build a simple graph (A-B1) on the png file.
After fixing a lot of misconfigurations, now I got:
Traceback (most recent call last):
File "/Users/zallaricardo/Documents/Python/test_png.py", line 7, in <module>
graph.write_png('graph.png')
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pydot.py", line 1809, in <lambda>
lambda path, f=frmt, prog=self.prog : self.write(path, format=f, prog=prog))
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pydot.py", line 1911, in write
dot_fd.write(self.create(prog, format))
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pydot.py", line 2023, in create
status, stderr_output) )
pydot.InvocationException: Program terminated with status: 1. stderr follows: Format: "png" not recognized. Use one of:
logout
And till now could not find a straight solution to my particular environment.
Any hint about how can I fix it?
Need to work for python 2.7 and mac os x 10.9.
My current installed packages:
cycler==0.9.0
decorator==4.0.4
graphviz==0.4.7
matplotlib==1.5.0
networkx==1.10
numpy==1.10.1
pydot2==1.0.33
pyparsing==1.5.7
PyPDF2==1.25.1
python-dateutil==2.4.2
pytz==2015.7
six==1.10.0
wheel==0.26.0
I just would like to reach the same result shown in https://pythonhaven.wordpress.com/2009/12/09/generating_graphs_with_pydot/

Could you try uninstalling pydot2 and install pydot?
$ pip uninstall pydot2
$ pip install pydot>=1.2.3
Without any change in the script, I got the following output

python - pyinstaller "RuntimeWarning: Parent module 'PyInstaller.hooks.hook-PIL' not found while handling absolute import" and "tcl" related errors

I get a warning message while trying to create exectable file using pyinstaller. This warning appeared after installing Pillow. Previously i nevre got any warnings and was able to make it through.
the warning i get by pyinstaller is:
7314 INFO: Analyzing main.py
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/PyInstaller-2.1.1dev_-py2.7.egg/PyInstaller/hooks/hook-PIL.Image.py:14: RuntimeWarning: Parent module 'PyInstaller.hooks.hook-PIL' not found while handling absolute import
from PyInstaller.hooks.shared_PIL_Image import *
Also when i tried to run the executable's exe/consol version of my code that lies inside the dist folder created by the pyinstaller (dist/main/main), these are displayed..
Traceback (most recent call last):
File "<string>", line 26, in <module>
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/PyInstaller-2.1.1dev_-py2.7.egg/PyInstaller/loader/pyi_importers.py", line 276, in load_module
exec(bytecode, module.__dict__)
File "/Users/..../build/main/out00-PYZ.pyz/PIL.PngImagePlugin", line 40, in <module>
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/PyInstaller-2.1.1dev_-py2.7.egg/PyInstaller/loader/pyi_importers.py", line 276, in load_module
exec(bytecode, module.__dict__)
File "/Users/..../build/main/out00-PYZ.pyz/PIL.Image", line 53, in <module>
File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/PyInstaller-2.1.1dev_-py2.7.egg/PyInstaller/loader/pyi_importers.py", line 276, in load_module
exec(bytecode, module.__dict__)
File "/Users/..../build/main/out00-PYZ.pyz/FixTk", line 74, in <module>
OSError: [Errno 20] Not a directory: '/Users/.../dist/main/tcl'
logout
[Process completed]
so, i tried by uninstalling pillow, installing tk tcl dev version. And then installed pillow. Even that didnt helped.
I also tried reinstalling pyinstaller,. didnt help too
Update 1:
It seems Pyinstaller.hooks.hook-PIL.py file was missing in the Pyinstaller/hooks directory. And it was missing on all platforms(Mac, windows and linux). This is the warning/error message that i get on windows, which is the same i got on mac and on linux.
Later i found a link which said, its just to need Python import machinery happy. so i created as said so. Then i dont get the same error on all platforms, But on mac i still get the PILImagePlugin,Image and FixTk errors

Solution for tcl:
I found what was going wrong,.. Every problem that i faced on OSX was the OS itself(exactly the macport). Python by default comes with the mac OS. And this version of python may be useful for just learning basic python, but is not suitable for Development purpose.
Installing brew's python helped. I followed this SO link. After doing these i was still getting errors. Later i had to change the paths on /etc/paths. Basically rearranging them should work. But still then i wasn't getting it right.
Then i had to change the .bash_profile, which worked for most users, But still i was getting mac's version of python and pip, not the brews version of python.
Finally i had to restart the machine for a couple of times and do the /etc/paths and .bash_profile steps repeatedly to get the system wide effect to accept brews version of python and pip
Solution for PIL:
just adding a file called hook-PIL.py with an empty content would serve the purpose. I found a link which was having the hook files content of pyinstaller.
The location to create
for mac : /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/PyInstaller-2.1.1dev_-py2.7.egg/PyInstaller/hooks/ Actually for mac this step wouldn’t be required. When we install python through brew and change the path, everything that you try to install later either through pip install or from source packages tend to choose a different path. And everything will be taken care of.
for windows:C:\Python27\lib\site-packages\PyInstaller-2.1.1.dev0-py2.7.egg\PyInstaller\hooks
**Please check if this is a valid path on your machine before creating the file and then create the file. And im not sure or i don't know if just adding an empty file is the right way. But it worked for me

ImportError: Entry point ('console_scripts', 'nosetests') not found

I am trying to launch the nosetests by following the instruction from the learnpythonthehardway tutorial.
I tried to run the nosetests form Powershell and got the following:
PS E:\python\projects\skeleton> nosetests
Traceback (most recent call last):
File "C:\Python27\Scripts\nosetests-script.py", line 9, in <module>
load_entry_point('nose==1.3.0', 'console_scripts', 'nosetests')()
File "C:\Python27\lib\site-packages\distribute-0.6.45-py2.7.egg\pkg_resources.py", line 343, in load_entry_point
return get_distribution(dist).load_entry_point(group, name)
File "C:\Python27\lib\site-packages\distribute-0.6.45-py2.7.egg\pkg_resources.py", line 2353, in load_entry_point
raise ImportError("Entry point %r not found" % ((group,name),))
ImportError: Entry point ('console_scripts', 'nosetests') not found

I know this is late but for anyone else who runs into this problem try running
sudo pip uninstall nosetests
pip uninstall nosetests
Then reinstall nosetests regularly.
If it still doesn't work try searching your laptop through finder for any other instances of nosetests and getting rid of those as well.
If that still doesn't work clear your trash bin as well. T

After hours of banging my head against my keyboard with the same issue, I finally have it working on my end.
Your question isn't clear about your setup, but I had the same error message (Import Error... entry point console scripts not found).
I was using pip to create my package, then at some point (months ago) switched to poetry. My poetry toml file didn't have the packages installed, nor the entry point!
Poetry add-ing the packages and adding this got it working for me:
[tool.poetry.scripts]
myCli = "myCli.main:cli"
I had a setup.py, but editing it won't do anything since setup.py is created during the build process.