My PYTHONPATH environment variable was accidentally deleted by a package during some testing. I don't have a back up of the path variable, but now I can't import any third party packages into python because I'm missing all the paths that were previously there.
Is there a way to recover just the standard PYTHONPATH variables?
I'm using Anaconda distribution with Python 3.6.
Windows 10.
I tried system restore, but this has failed for my only restore points, another issue I have to sort out.
Related
I have a device with Python 3.7 pre-installed, without any pip package.
I created the program on my local machine with some packages in my venv (I have a requirements.txt file) and it works perfectly.
My problem is that now I want to create a directory with my programs and upload it to my device. This doesn't work because I don't have additional packages installed.
My question: Is there a way to export the installed package to a directory in my program files and import it locally and not from venv?
Copy the all the venv modules to some directory and modify PYTHONPATH variable when running your program, append your modules directory path to it.
man python3
PYTHONPATH
Augments the default search path for module files. The format is the same as the shell's $PATH: one or more directory
pathnames separated by colons. Non-existent directories are silently ignored. The default search path is installation
dependent, but generally begins with ${prefix}/lib/python<version> (see PYTHONHOME above). The default search path is al‐
ways appended to $PYTHONPATH. If a script argument is given, the directory containing the script is inserted in the path
in front of $PYTHONPATH. The search path can be manipulated from within a Python program as the variable sys.path.
In general, you have the following options to run a python script on another device than the one you developed the script on:
Generate an executable (for example with the package pyinstaller). With that solution, it is not required to have python installed on your device, as everything is embedded in the executable
If you have python installed on the device (like your case), you can just run it on it. However, if you have dependency (from PyPi or Conda), you must also install them on your device
If you have access to internet and have your requirements.txt file, you can just run pip install -r requirements.txt
If you don't have access to internet, you can either:
download the wheel for each package and then ship it to your device
just ship to your device the contents of the folders lib and lib64 of your virtual environnement folder .venv of your local machine (I hope you are using one python -m venv .venv) into the virtual environment of your device
I don't know how it happened, but my sys.path now apparently contains the path to my local Python project directory, let's call that /home/me/my_project. (Ubuntu).
echo $PATH does not contain that path and echo $PYTHONPATH is empty.
I am currently preparing distribution of the package and playing with setup.py, trying to always work in an virtualenv. Perhaps I messed something up while not having a virtualenv active. Though I trying to re-install using python3 setup.py --record (in case I did an accidental install) fails with insufficient privileges - so I probably didn't accidentally install it into the system python.
Does anyone have an idea how to track down how my module path got to the sys.path and how to remove that?
I had the same problem. I don't have the full understanding of my solution, but here it is nonetheless.
My solution
Remove my package from site-packages/easy-install.pth
(An attempt at) explanation
The first hurdle is to understand that PYTHONPATH only gets added to sys.path, but is not necessarily equal to it. We are thus after what adds the package into sys.path.
The variable sys.path is defined by site.py.
One of the things site.py does is automatically add packages from site-packages into sys.path.
In my case, I incorrectly installed my package as a site-package, causing it to get added to easy-install.pth in site-packages and thus its path into sys.path.
By error, I forgot to specify the WORKON_HOME variable before creating my virtual environments, and they were created in /root/.virtualenvs directory. They worked fine, and I did some testing by activating certain environment and then doing (env)$ pip freeze to see what specific modules are installed there.
So, whe I discovered the workon home path error, I needed to change the host directory to /usr/local/pythonenv. I created it and moved all the contents of /root/.virtualenvs directory to /usr/local/pythonenv, and changed the value of WORKON_HOME variable. Now, activating an environment using workon command seems to work fine (ie, the promt changes to (env)$), however if I do (env)$ pip freeze, I get way longer list of modules than before and those do not include the ones installed in that particular env before the move.
I guess that just moving the files and specifying another dir for WORKON_HOME variable was not enough. Is there some config where I should specify the new location of the host directory, or some config files for the particular environment?
Virtualenvs are not by default relocatable. You can use virtualenv --relocatable <virtualenv> to turn an existing virtualenv into a relocatable one, and see if that works. But that option is experimental and not really recommended for use.
The most reliable way is to create new virtualenvs. Use pip freeze -l > requirements.txt in the old ones to get a list of installed packages, create the new virtualenv, and use pip install -r requirements.txt to install the packages in the new one.
I used the virtualenv --relocatable feature. It seemed to work but then I found a different python version installed:
$ . VirtualEnvs/moslog/bin/activate
(moslog)$ ~/VirtualEnvs/moslog/bin/mosloganalisys.py
python: error while loading shared libraries: libpython2.7.so.1.0: cannot open shared object file: No such file or directory
Remember to recreate the same virtualenv tree on the destination host.
I have to present my application on another PC, which does not have the modules that I use already installed so I have to locally import everty pythom module that I use. I use a lot of them, like: OpenCV, TesorFlow, Keras, Kivy, sci-kit-image, etc. I discovered that all my python packages are installed in the directory site-packages, which is a part of the tree where is python installed. I want to copy-paste my site-packages directory to the other PC and import all that I need when my app has to run on the other PC. How do I set all modules from site-packages locally to be available for import in my app?
The second solution I could think of would be to download all the modules from the git and official sites, and import them into my app, but it's hard labour and I have to write a .bat file to install them... but I'm pretty sure I don't have the permission to install anything...
Is there a way for my first solution? pls I really need to know
Edit: I use python 3.6
If you copy the whole package directory to your project directory, it should work. It then will be imported as though it is your own module.
Look at this: How does python find a module file if the import statement only contains the filename?
Once a program is installed in Linux, sometimes I find out that it is easier to put in a different location. In general, what is the significance of the location of the files of an installed program on Linux?
Often the advice on the internet is to add the (wrong or inconvenient) paths to environment variables. I'd much rather move the files to locations where they are automatically found by commands and programs.
One recent example is site-packages of Python. My Python did not appear to check the PYTHONPATH variable, moving the libraries there to the Python2.7/ directory worked well.
Now Ia m facing the same issue with OpenCV.
I also wonder why Linux installation does not prompt (like Windows) for the desired installation directory and why, so often, things wind up in places where they don't work?
In general, programs are installed in /usr/bin (for binaries) and /usr/lib, or a specific path to that specific linux distro, so that any program that you install that uses a specific library/program will search in that path for it. If you install a program in a different path, let's say /home/user/program, it will be installed locally and other programs won't be able by default to access it.
You can install any program wherever you want. However, it is good use to use the repo and install them in the general path.
I don't know how you install programs, but I use apt-get and dpkg on Ubuntu. You can also install some python modules this way.
Generally you are supposed to use the package system provided by your distro (IMHO).
If you do not use packages then you are on your own.
About PYTHONPATH. Did you add it to your .bashrc and made sure that it was set in the terminal you are using?
Also please see:
http://en.wikipedia.org/wiki/Filesystem_Hierarchy_Standard