1

I created a python file and used some packages. I installed packages on a virtual Environment. Now, when I try to run that file, it run on the default installed interpreter and I have to activate the virtual Environment every time I have to run that file. Is there any way possible to do that. In conclusion: The code from which the file can select the place where to look for the packages.

Ishant
  • 21
  • 2
  • 1
    It would be good to give more information about the paths and operating system you use to create a better answer ;-) – Frank Jan 10 '22 at 14:39

3 Answers3

1

You can add the path to the virtual environment's interpreter directly to the shebang at the top of the script. For example, if your virtual environment is stored at /home/ishant/venv, the shebang would be

#!/home/ishant/venv/bin/python

Then, if you execute your script directly (after making it executable with chmod +x or the like), your virtual environment will be used.

(Activating a virtual environment simply updates your PATH variable so that python resolves to the virtual environment, rather than your "regular" environment. You can always access the tools in the virtual enivironment directly instead.)

chepner
  • 497,756
  • 71
  • 530
  • 681
  • This makes it usable from bash with direct execution, but only for user 'ishant'. Do only use that for single user experiments. – Frank Jan 10 '22 at 13:41
  • I am on windows. and can you specify how can i use "shebang". I have no idea about that. I just copied what you gave me and pasted it over. – Ishant Jan 10 '22 at 14:05
  • Sorry, I don't know the common ways of executing a Python script under Windows. – chepner Jan 10 '22 at 14:05
  • Have a look at https://stackoverflow.com/a/70653317/9857620 there's a windows solution with absolute paths (shebang is posix only). – Frank Jan 10 '22 at 14:35
0

Command line only (Linux)

Put this in your ~/.bashrc and create the virtual env with name 'venv' inside the project root:

function cd() {
  if [[ -d ./venv ]] ; then
    deactivate
  fi

  builtin cd $1

  if [[ -d ./venv ]] ; then
    . ./venv/bin/activate
  fi
}

When cd-ing into a directory, it searches for a virtualenv named venv and disables when leaving.

Alternative with absolute paths (Linux and Windows)

In cases where you want to run the script without a bash, you could run it with the absolute path to the python interpreter inside the virtualenv.

This is from inside the project dir:

# Posix:
/path/to/virtualenvname/bin/python run.py

# Windows:
C:\path\to\virtualenvname\Scripts\python.exe run.py

Or if you want to execute it from outside of the project dir:

# Posix:
/path/to/virtualenvname/bin/python /path/to/projectdir/run.py

# Windows:
C:\path\to\virtualenvname\Scripts\python.exe C:\path\to\projectdir\run.py
Frank
  • 1,959
  • 12
  • 27
  • 1
    Note that this won't actually work when running the script from anywhere but its own directory (actually, the ``venv``'s if the two aren't the same). It won't work when invoking the script via the ``PATH`` or any non-trivial absolute/relative path. – MisterMiyagi Jan 10 '22 at 13:48
  • Thanks, you're right. I edited my post. – Frank Jan 10 '22 at 14:12
-2

Okk So i got your point what i think is why not to add some function in your code so that whenever you excute it it will automatically use vitual environment

--code for linux

import os

os.system("source <virtualenv_name>/bin/activate")

--code for windows

import os

os.system("<virtualenv_name>/bin/activate")

And at last line add

os.system("deactivate")

Add these lines to beginning of your programm see if it works.

May this help you solving your probelem

Thanks!!

Pratham
  • 7
  • 4
  • It says source is not recognized as an internal or external command. – Ishant Jan 10 '22 at 13:35
  • This forces everyone working with your code to create this virtualenv. Do only use that for single user experiments. – Frank Jan 10 '22 at 13:40
  • See i have edited my answer again hope it works for you !! – Pratham Jan 10 '22 at 13:40
  • Did you actually try these? ``source`` and the ``activate`` script set the environments *in the current shell* – which is gone once ``os.system`` completes. – MisterMiyagi Jan 10 '22 at 13:42
  • i added the new one for windows but now its saying that: `'venv' is not recognized as an internal or external command` and this is what i added to it: ``` import os os.system("venv/Scripts/activate") ``` – Ishant Jan 10 '22 at 13:53