Python - HackMD

# Python ### Python3 - Set up virtual enviroment Check this article https://www.dataquest.io/blog/a-complete-guide-to-python-virtual-environments/ NOTE: There are two tools for setting up virtual environments, virtualenv and venv, that we can use almost interchangeably. virtualenv supports older Python versions and needs to be installed using the pip command. In contrast, venv is only used with Python 3.3 or higher and is included in the Python standard library, requiring no installation. Create a dir for the project ```bash mkdir myproject ``` Create the virtual env ```bash= python3 -m venv myproject/venv ``` Activate the virtual env ```bash source myproject/venv/bin/activate ┌──(venv)─(kali㉿kali)-[~/Downloads] └─$ ┌──(venv)─(kali㉿kali)-[~/Downloads] └─$ which python /home/kali/Downloads/myproject/venv/bin/python ┌──(venv)─(kali㉿kali)-[~/Downloads] └─$ python --version Python 3.10.7 ``` Installing Packages in a Python Virtual Environment ```bash ┌──(venv)─(kali㉿kali)-[~/Downloads] └─$ pip list Package Version ---------- ------- pip 22.2 setuptools 59.6.0 ┌──(venv)─(kali㉿kali)-[~/Downloads] └─$ pip install --upgrade pip ``` Install specific requirements for your project ```bash ┌──(venv)─(kali㉿kali)-[~/Downloads] └─$ pip install -r requirements.txt ``` ### Install python2 and set up a virtual environment Check this article https://realpython.com/intro-to-pyenv/#specifying-your-python-version #### Install python2 Check this article https://www.kali.org/docs/general-use/using-eol-python-versions/ Install dependencies ```bash sudo apt install -y build-essential libssl-dev zlib1g-dev libbz2-dev libreadline-dev libsqlite3-dev wget curl llvm libncurses5-dev libncursesw5-dev xz-utils tk-dev libffi-dev liblzma-dev python3-openssl git ``` The following configuration apply if you are using ZSH shell Check if you are using ZSH ```bash= ps -p $$ ``` or ```bash echo $SHELL ``` Install pyenv.run https://github.com/pyenv/pyenv-installer ```bash curl https://pyenv.run | bash ``` If we are using ZSH then we will now add the proper lines to our .zshrc. Update the shell to ensure autocomplete for pyenv is functional ```bash= echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.zshrc echo 'export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.zshrc echo -e 'if command -v pyenv 1>/dev/null 2>&1; then\n eval "$(pyenv init --path)"\nfi' >> ~/.zshrc ``` Lets continue with the setup. Reboot shell ```bash exec $SHELL ``` Check pyenv ```bash pyenv ``` We can now install Python 2 and set it as our default Python version: ```bash pyenv install 2.7.18 pyenv global 2.7.18 ``` Check python2 version ``` pyenv versions python ``` We can now install dependencies as needed for whatever tools we are using. When we want to swap back to Python 3, we just need to install python 3 and set the global to be system. One thing to keep in mind is to stick with installing the dependencies via pip ```bash= pyenv install --list | grep 3.10 pyenv install 3.10.7 ┌──(kali㉿kali)-[~/Downloads] └─$ pyenv versions system * 2.7.18 (set by /home/kali/.pyenv/version) 3.10.7 pyenv global 3.10.7 ┌──(kali㉿kali)-[~/Downloads] └─$ pyenv versions system 2.7.18 * 3.10.7 (set by /home/kali/.pyenv/version) ``` #### Set up the virtual environment Make a note of the full file path to the custom version of Python you just installed ```bash which python /home/kali/.pyenv/shims/python ``` Install virtual-event ```bash sudo apt install python3-virtualenv ``` Create the virtual env using python2 virtualenv -p \<path to python2\> \<virtual dir\> ```bash= virtualenv -p /home/kali/.pyenv/shims/python venv ``` Activate the virtual environment ```bash source venv/bin/activate ``` Now you will work with python2 ``` ──(venv)─(kali㉿kali)-[~] └─$ python -V Python 2.7.18 ┌──(venv)─(kali㉿kali)-[~] └─$ pip --version pip 20.3.4 from /home/kali/venv/lib/python2.7/site-packages/pip (python 2.7) ``` ## Pyenv MacOS https://github.com/pyenv/pyenv#how-it-works ### Visual Studio Code - Set up a virtual environment Opening the Command Palette (Shift+⌘+P) Select Python Interpreter Then open Terminal (Control+Shift+P) ```bash= python3 -m venv .venv ``` Accept the prompt to allow you to select it for the workspace.