Virtual environment

You want each project to have their own environment. Virtual environments isolates Python projects by creating separate environments. Each environment has its own installation of Python packages, which avoids conflicts between different projects.

Pip

The standard package manager for Python, used to install, upgrade, and remove Python packages

• You basically download external modules using pip
  • As of Python 3.4, it comes installed in Python by default
• Uses requirements.txt for dependency management
• You need to handle virtual environments separately

Just python

python3 -m pip install PACKAGE_NAME

With virtual environment

#Create virtual environment
python -m venv env
 
# Activate virtual environment  
source env/bin/activate
 
#Install requirements
pip install -r requirements.txt 
 
# Listing al installed packages
pip freeze
pip freeze > requirements.txt
 
# When using a virtual environment, `sys.executable` points to the Python executable within that virtual environment. This helps ensure that you are using the correct Python interpreter when running scripts or commands.
python
>>> import sys
>>> sys.executable #'use/bin/python'

Pipenv

https://www.youtube.com/watch?v=6Qmnh5C4Pmo&t=1s

• 시간나면 볼것

Manages both virtual environments and project dependencies in a more integrated way. It aims to provide a unified tool for dependency management and virtual environment creation.

• Automatically manages Pipfile and Pipfile.lock which replace requirements.txt for specifying and locking dependencies.
• Automatically creates and manages a virtual environment for your project, ensuring isolation of dependencies.
• Pipenv cheat sheet
  • https://gist.github.com/bradtraversy/c70a93d6536ed63786c434707b898d55

pip install pipenv
 
# Creating a new project and virtual environment, generating a Pipfile in the directory
pipenv install
 
# Activating the environment
pipenv shell
 
# Installing the Python package you want to install
# Updating 'Pipfile' and 'Pipfile.lock'
pipenv install package_name

Pip vs Pipenv install

pip install langchain

• Installs the langchain package directly into the currently active Python environment, which could be either the global environment or a manually created virtual environment pipenv install langchain
• Installs the langchain package into a virtual environment managed by pipenv. If no virtual environment exists, pipenv will create one for you.