Skip to content

Latest commit

 

History

History
165 lines (123 loc) · 5.03 KB

PYTHON-VIRTUAL-ENVS.md

File metadata and controls

165 lines (123 loc) · 5.03 KB
Raw

Install pyslam virtual environment

The following instructions allow you to create a custom pyslam virtual environment by using the package python3-venv. You will be able to run pyslam scripts within such environment.

If you are under macOS, please check this other document.

Installation

In order to run main_slam.py with venv, get in the root of this repository and run the following command:

$ ./install_all_venv.sh

This will compile all the required thirdparty packages and create a pyslam python virtual environment.

Usage

Now, you can run:

$ . pyenv-activate.sh   # Activate pyslam python virtual environment. This is just needed once in a new terminal.
$ ./main_vo.py

or

$ . pyenv-activate.sh   # Activate pyslam python virtual environment. This is just needed once in a new terminal.
$ ./main_slam.py

If you want to use a new terminal, recall that you need to activate the pyslam environment as explained in this section

Create a pyslam python virtual environment

You don't need this if you already launched the main install script install_all_venvsh (see above). In order to create a custom pyslam python virtual environment, get in the root of this repository and run the following command:

$ . pyenv-create.sh

N.B.: do not forget the dot! (without '/' !)

This will create and activate a python virtual environment pyslam where to safely run pyslam scripts.

Activate the created pyslam environment

Run the following command:

$ . pyenv-activate.sh

Now, you can launch pySLAM scripts.

Deactivate pyslam environment

Run the command:

$ deactivate

Delete pyslam environment

To delete the pyslam environment, run

$ . pyenv-delete.sh

General Notes About Python Virtual Environments

Below, you can find some useful details. The scripts mentioned above make the work for you.

Install virtualenv package

sudo apt install python3-venv

Where to create a new virtual environment

You can create a new directory where to deploy the new environment with name venv-name

$ mkdir -p ~/.python/venvs/<venv-name> 
$ cd ~/.python/venvs/<venv-name>

Create a new virtual environment inside the directory:

$ python3 -m venv <venv-name>

Activate the environment

In order to use this environment’s packages/resources in isolation, you need to “activate” it. To do this, just run the following:

$ source ~/.python/venvs/<venv-name>/bin/activate

This will return in your shell a prefixed prompt with the name of your environment

(env) $

This is the indicator that env is currently active, which means the python executable will only use this environment’s packages and settings.

Deactivate the environment

Run the following command

(env) $ deactivate

This will removed the prefixed prompt.

Install packages from requirements.txt

You can generate a requirements.txt file by running:

$ pip3 freeze > requirements-pip3.txt

You can install from such a file by runnning:

$ pip3 install -r requirements-pip3.txt

N.B.: the file requirements.txt generated by pip3 cannot be used with conda (and viceversa)!

Check if you are in an activated virtual environment

From shell check the shell prefix, as explained above

From a script, you can use the following code:

function get_after_last_slash(){
    ret=$(echo $1 | sed 's:.*/::')
    echo $ret 
}
function get_virtualenv_name(){
    cmd_out=$(printenv | grep VIRTUAL_ENV)
    virtual_env_name=$(get_after_last_slash $cmd_out)
    echo $virtual_env_name
}

the function get_virtualenv_name returns the name of the path of the activated virtual environment. If no virtual environment has been activated then the output will be empty.

Links