I use Pycharm to create and manage my virtualenvs in my projects.
The problem is that after adding a library with pycharm, when I type the command (pip3 freeze --user), the library does not appear in the command result.
I have to manually type the pip install command each time so that the library is visible.
What manipulation should I do in PyCharm to solve this problem?
For what you are saying, the first thing that comes to mind is that you should use:
pip freeze
And not
pip3 freeze
Because the command mapped to the pip version when you have virtualenv activated is the first. Note that for installing you seem to use pip, and not pip3
Moreover, the --user option afaik is related to the packages installed in the user folder:
--user Install to the Python user install directory for your platform. Typically
~/.local/, or %APPDATA%\Python on
Windows. (See the Python documentation for site.USER_BASE for full details.)
If your packages are installed in the virtualenv folder, I would tell you to not use that option.
Also please make sure you have your virtualenv activated. In linux you can do so by source path/to/virtualenv/activate
Edit
I understand that the reason you are using pip3 is because you may have different versions of Python in your machine. Let me explain you a bit further how it works, because version management is usually a headache for many programmers and it is common to find problems when doing so.
If you install different versions of Python in your linux machine, and you do that as root, then the installation will proceed for the whole system. Usually Python2 installation folder for Linux machines is /usr/bin/python. However, I am uncertain of which directory is used for Python3 installations. You can check that easily by doing whereis python3. You can serach the path to binary of any command by doing whereis command. Note that this works also for whereis python as far as you don't have virtualenv activated.
Aditionally, the link to the binary of a command (or the set of instructions to be exectued, more broadly) is defined in certain folders in Linux, depending on whether you created the command as root or as a user, and possibly also on the distro. This works differently in Windows, that uses the Registry Edit utility to handle command mappings. When you enable your virtualenv, what you are doing is creating an environment that enables mapping system commands such as python to the Python installation in your virtualenv folder.
When you disable the virtualenv, the command points again to the default installation path. Same happens with pip, so incorrect usage of this tool may result in different packages being installed in different locations, and therefore not appearing available for the right Python version at any given circumstance.
In Linux, environment variables are shell dependent, though you can write them out with echo $variable and set them with variable=value (from bash). The search path is simply called PATH and you can get yours by typing echo $PATH.
Source: https://askubuntu.com/a/262073/426469
I encourage you to check other questions in SE network such as this: https://unix.stackexchange.com/a/42211/96121, to learn more about this.
Addendum
Quick tip: it is common to use the pip freeze command as follows:
pip freeze > requirements.txt
It is a standard that leads to understanding that modules in such file are required for the correct functioning of your application. That lets you easily exclude the virtualenv folder when you install the program in another computer, since you can readily know the requriments for a fresh installation. However, you can use the command as you want.
Related
I need libv8-3.14 to run some R packages on linux, but I don't have root access/sudo access on the linux computer I'm using so I'd like to install an external folder instance of libv8-3.14. I've seen R packages reference this as external as CDFLAG="folder/v8-3.14" so I know it is possible.
I'm new(ish) to linux but I've installed external libraries before with tar.gz files which then have a configure file in them, which I set the external folder with ./configure --prefix==/folder/loc, but the only downloads I can find of libv8 are .git (which I can't get to work either).
How can I install an libv8-3.14 to a folder and install so I can set:
export PATH=$PATH:/path/to/install/
and
export `LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/path/to/install/`
I had the exact same problem. In case somebody in the future comes across this post, I will leave my suggestions and how it worked out in the end. Also, all credits go to an experienced colleague of mine.
The most sure thing to do is to consult IT, or someone who has already had the same problem, there is usually a workaround these issues.
A way you can do it yourself:
Create an anaconda environment, you can name it 'V8' or something (make sure the environment is based on the latest python version, or recent enough for r-v8).
activate it
install the conda version of the V8 R interface with conda install -c conda-forge r-v8
That's it. Whenever you need V8, fire up your environment beforehand, and it should be A-OK.
Further advice: If you run into errors when installing r-v8, it may be a good idea to update your conda and all the packages. However, depending on your conda version conda update conda and conda upgrade --all MAY BREAK your conda installation, so be careful. (For further information on this problem, see the endless complaints of people in this issue: https://github.com/conda/conda/issues/8920).
V8 doesn't use autotools, so it has no ./configure. In fact, it provides no installation facilities at all, because it is meant for embedding, not installing.
What I would try is to download the Ubuntu package (guessing from your other question, you are on Ubuntu, right?) for the right architecture from https://packages.ubuntu.com/trusty/libv8-3.14.5, and extracting it manually. .deb files are just ZIP archives.
As a side note, there's no point in setting PATH, because libv8, being a library, provides no executables. LD_LIBRARY_PATH is all you need.
I am using ubuntu 18.04. I have Python-3.6.6 installed as a default version. But for practice I have installed Python-3.6.5 from source code to a directory where I wanted to install it and changed the .bashrc file accordingly. But it is showing me the default python3 path when I call "which" command.
How to use the python version which one I have installed recently?
If you only want to run some practice scripts you can select directly which python you want to use for your script. In the command line, e.g. type
PYTHONPATH=/foo/bar/python365 python somescript.py
where /foo/bar/python365 points to your python-3.6.5
You can also change your PYTHONPATH variable to look first in the python-3.6.5 folder before it looks to the default python (3.6.6) you had installed before. However, I do not recommend this, since it will make all python applications choose the python-3.6.5 as default. For extended practice with python-3.6.5 consider a virtual environment or an anaconda environment.
You should use virtualenv or something similar, like pipenv, I myself use virtualenv.
Here's a guide on how to do that: https://docs.python-guide.org/dev/virtualenvs/
virtualenv is a bit lower level and so not that intuitive to use, but since I used virtualenv before I found pipenv, I just stuck with it, while adding a few aliases to my .bashrc to make it easier.
I used two different python versions because discord.py would break on 3.7 (that doesn't seem to be the case anymore, but I still have it setup with 3.6 and 3.7), so here's what my .bashrc for two different versions looked like, this is on windows, but if you are on unix system or macOS (I want to make this answer as general as possible, it works the same on all operating systems really), just change the paths to lead to your interpreters (whichever you have) and don't use winpty:
alias python36="winpty C:/Users/Hevaesi/AppData/Local/Programs/Python/Python36-32/python.exe"
alias python37="winpty C:/Users/Hevaesi/AppData/Local/Programs/Python/Python37-32/python.exe"
alias pip36="C:/Users/Hevaesi/AppData/Local/Programs/Python/Python36-32/python.exe -m pip"
alias pip37="C:/Users/Hevaesi/AppData/Local/Programs/Python/Python37-32/python.exe -m pip"
alias venv36="python36 -m virtualenv"
alias venv37="python37 -m virtualenv"
alias python="winpty python"
Now, to use Python 3.6, I use venv36 venv in my project folder, and it setups Python 3.6 environment, using venv37 venv would create Python 3.7 environment.
I also wrote a function to make activating less of a hassle (again, this is in bashrc)
activate() {
if [ "$#" == 1 ]; then
source "$1/Scripts/activate"
else
echo "Usage: activate <env_name>"
fi
}
So, after I created my env once, I go to project folder, type activate venv and it starts up whatever version I wanted the project to have all by itself, to run my project I just use python myfile.py, when virtual environment is activated, it will use the interpreter that's in active virtual environment, regardless of what you have in your PATH variable. Also, using pip will automatically install to your virtual environment, not your actual installation, meaning global package list will be clean, or in best case, completely empty.
You should only install what you need and keep it separate environments, normally you use a single environment per project. Well, unless your project is client/server at once (for whatever reason) and server uses different libraries than client, for example, more of them, client environment could have less modules since that's what the server is for, to provide something without having to do it yourself, so they could be two projects in one, hence two different environments, separating dependencies based on what the "unit" in the project really needs.
Note: you have to install virtualenv (or pipenv or whatever you want to use really) into all of your python installations, if you want to create virtual environments from them, that's what pip36 and pip37 here is for - for installing packages directly into actual python installations, for now, I only had to do pip36 install virtualenv and pip37 install virtualenv.
I reinstalled Miniconda (version 4.3.21) at c:\Miniconda3, created an environment named data and also installed some packages in this environment. The Python version came with this Conda is 3.6. However, before installing the Miniconda, version 3.4 of Python was already installed on my system (location c:\python34). OS is Windows 7 (32 bits).
On command line, I can run command like conda info --envs or conda create -n data. I can even open Python IDLE by running idle command which opens the IDLE for Python which came wih Miniconda. But when I try to run activate data, it shows this error.
However, when I run command line as administrator, I am able to activate environment. If I remember correctly, earlier I was able run all commands without needing any admin privileges. Why does this happen?
So what is happening is that your user likely has the original Python executable(or old Miniconda Python) in your users PATH and this is found before Minconda Python. When run as Admin(because installing to C:\Miniconda requires admin privileges) it finds the correct executable that is in the System PATH. Having both a standard Python and Miniconda in your user Path will cause issues as it will use the first Python.exe found based on your PATH.
Check Computer > Properties > Advanced System Settings > Environment Variables.
Put Minconda before the standard Python or remove the standard python(there is no difference between standard python and the python included with Miniconda as they both come from python.org). You may also need to set the permissions on the entire C:\Miniconda directory for your user. Even though you have admin access you will still need to escalate privileges if you don't set permissions for your actual user.
I am using Python 3.5.2 version on Windows 7 and tried using python3 app.py. I am getting this error message:
'python3' is not recognized as an internal or external command,
operable program or batch file.
Is there any specific cause about why the python3 command is not working?
I also verified that the PATH is added to environment variables.
There is no python3.exe file, that is why it fails.
Try:
py
instead.
py is just a launcher for python.exe. If you have more than one python versions installed on your machine (2.x, 3.x) you can specify what version of python to launch by
py -2 or
py -3
You can also try this:
Go to the path where Python is installed in your system. For me it was something like C:\Users\\Local Settings\Application Data\Programs\Python\Python37
In this folder, you'll find a python executable. Just create a duplicate and rename it to python3. Works every time.
Python3.exe is not defined in windows
Specify the path for required version of python when you need to used it by creating virtual environment for your project
Python 3
virtualenv --python=C:\PATH_TO_PYTHON\python.exe environment
Python2
virtualenv --python=C:\PATH_TO_PYTHON\python.exe environment
then activate the environment using
.\environment\Scripts\activate.ps1
Yes, I think for Windows users you need to change all the python3 calls to python to solve your original error. This change will run the Python version set in your current environment. If you need to keep this call as it is (aka python3) because you are working in cross-platform or for any other reason, then a work around is to create a soft link. To create it, go to the folder that contains the Python executable and create the link. For example, this worked in my case in Windows 10 using mklink:
cd C:\Python3
mklink python3.exe python.exe
Use a (soft) symbolic link in Linux:
cd /usr/bin/python3
ln -s python.exe python3.exe
In my case I have a git hook on commit, specified by admin. So it was not very convenient for me to change the script (with python3 calls).
And the simplest workaround was just to copy python.exe to python3.exe.
Now I could launch both python and python3.
If python2 is not installed on your computer, you can try with just python instead of python3
For Python 27
virtualenv -p C:\Python27\python.exe django_concurrent_env
For Pyton36
virtualenv -p C:\Python36\python.exe django_concurrent_env
Enter the command to start up the server in that directory:
py -3.7 -m http.server
I had a related issue after installing windows 11, where python3 in cmd would open the windows store. I was able to sort it out between this post and this other one. In short, I reinstalled python and made sure to add it to PATH. Then, in settings, Apps > Apps & Features > App Execution aliases. Here, all I had to do was make sure that every single python .exe (including idle and pip) were turned off EXCEPT FOR the python3.exe alias. Now it works like a charm.
FWIW:
The root of this issue is not with you or with python. Apparently, Microsoft wanted to make installing python easier for young kiddos getting interested in coding, so they automatically add an executable to PATH. For those of us that already have this executable, it can cause these issues.
Found out instead press the play button the top right and it should work in visual studios:
Do not disable according to first answer
Saying python3 in the command will not work by default.
After figuring out the problem with the modules (Solution): https://youtu.be/paRXeLurjE4
Summary:
To import python modules in case of problem to import modules:
Hover over python in search:
Click open in folder
Hover over and right click
click properties
copy everything in path before \python.exe
close those windows
For cmd (administrator):
cd --path that was copied--
then python -m pip install --upgrade pip
cd Scripts
pip install "Name of Package" such as pip install --module (package) --
Im on win10 and have 3.7, 3.8 and 3.10 installed.
For me "python" launches version 3.10 and does not accept commands (like -3.7), "py" launches newest version but does accept commands, and "python3" does nothing.
Uninstalled 3.10 and "python" now does nothing, and "py" launches 3.8.
I am unable to add a comment, but the mlink option presented in this answer above https://stackoverflow.com/a/55229666/8441472 by #Stanislav preserves cross-platform shebangs at the top of scripts (#!/usr/bin/env python3) and launches the right python.
(Even if you install python from python.org, Windows will direct you to the app marketplace nowadays if you type python3 on the command line. If you type python on the same cli it will launch the python.org version repl. It leads to scripts that generate no output, but more likely silently failed completely. I don't know ho common this is but have experienced it on a couple of different devices)
If you have this at the top of your script to ensure you launch python3 and don't feel like editing everything you own, it is not a bad approach at all... lol.
meaning. I call a program. Example 'pip' (since I am having trouble with pip) and what does the Linux system do to find that program?
I'm having trouble with a pip installation and im trying to understand what happens under the hood when I type pip or any program into the terminal and press enter.
My hope is this allows me to fix the issue.
if you wish to know what issue I am having it is ImportError: No module named 'pip'
Linux will search for all available directories listed in the environmental variable PATH, and if it find pip from any path, it will try to execute it. And then in case the file pip has executable permission for the user, system will execute the command.
In general the shell searches through the directories listed in the PATH variable to find a file with the name you typed in. If you want to find out which file the shell is actually trying to run, on a unix-like system (read not windows), run which pip. I believe the windows equivalent is where pip, but don't quote me on that.
The specific error you are encountering, however appears to be the result of python being run something like python -m pip which means Python, please run the module named pip. Given that some file exists named pip on your system that tries to run pip, I am guessing one of two things is happening.
Either you have deleted some of the files somehow, in which case you should attempt to reinstall pip
Or you have changed which python is the default python, and you don't have a pip module in the python you are using now.
To test the last theory, try running which python and if there is a 2 in the path, then run python3 -m pip to see if the pythons got mixed up. Conversely if your are on a system that uses python3 by default, you will see a 3 in the result of the above command, and you can try python2 -m pip.
Hope that helps clear up the mess that is Python versioning.