how to execute the following command in google colab. export PYTHONPATH=/project/pylib/src:$PYTHONPATH

!export PYTHONPATH=/project/pylib/src:$PYTHONPATHit is not affect.

3 Answers

Edit 2020-11-12

Using `%` instead of `!` retains any changes to all cells in the session. So, we can use that to set the environment variable `PYTHONPATH`. However, export doesn't work in colab. `%env` can be used to set the environment variable.

! echo $PYTHONPATH %env PYTHONPATH="$/env/python:/content/gdrive/My Drive/Colab Notebooks/MNIST_Classifier/src" ! echo $PYTHONPATH 

Output:

/env/python /env/python:/content/gdrive/My Drive/Colab Notebooks/MNIST_Classifier/src 

Initial Answer

The following worked for me

! echo $PYTHONPATH import os os.environ['PYTHONPATH'] += ":/content/gdrive/My Drive/Colab Notebooks/MNIST_Classifier/src" ! echo $PYTHONPATH 

Output:

/env/python /env/python:/content/gdrive/My Drive/Colab Notebooks/MNIST_Classifier/src 

Sources:

The answer depends on why you want to do this.

For example, if you want to add the path to your current Python session so that Python's import mechanism finds modules located in that directory, you can do this:

import sys sys.path.insert(1, "/project/pylib/src") 

If you want to modify the environment variable itself (which won't affect the paths used in your current Python session) you can use the %set_env magic:

%set_env PYTHONPATH=/project/pylib/src:/env/python 

In my colab session (tested on 8 June 2022)

!echo $PYTHONPATH 

&

import os os.environ['PYTHONPATH'] 

outputs /env/python

But

import sys print(sys.path) 

outputs

['', '/content', '/env/python', '/usr/lib/python37.zip', '/usr/lib/python3.7', '/usr/lib/python3.7/lib-dynload', '/usr/local/lib/python3.7/dist-packages', '/usr/lib/python3/dist-packages', '/usr/local/lib/python3.7/dist-packages/IPython/extensions', '/root/.ipython'] 

So, in scenarios where you perform !git clone

import sys sys.path.insert(1, "/content/some_repo") from some_package.utils import some_func #located in some_repo 

will work rather than the first two options. I added /content/ because current working dir !pwd is /content/