Python

Python is a high-level, general-purpose programming language. Its design philosophy emphasizes code readability with the use of significant indentation. Python is dynamically typed and garbage-collected. It supports multiple programming paradigms, including structured, object-oriented and functional programming.

Packages and modules

A module is a file containing Python definitions and statements. The file name is the module name with the suffix .py appended. A package is a collection of Python modules: while a module is a single Python file, a package is a directory of Python modules

Structure of Python package

Structure of Python package. Source: Python Geeks

PIP

PIP is a package manager for Python packages, or modules if you like. It is used to install and manage software packages written in Python. You can install, uninstall and upgrade packages with the help of pip command. It also helps to manage dependency between packages.

  • pip --version - check pip version

  • pip list - list installed packages

  • py -m pip install --upgrade pip - upgrade pip

  • pip freeze > requirements.txt - save all installed packages in requirements.txt file

  • pip install -r requirements.txt - install all packages from requirements.txt file -r stands for requirements

  • py -m pip install <package_name> - install package (it is the same as pip install <package_name>)

Virtual environment

Virtual environment is a tool that helps to keep dependencies required by different projects separate by creating isolated Python virtual environments for them.

Virtual environment can be created by using venv module. To create a virtual environment, decide upon a directory where you want to place it, and run the venv module as a script with the directory path: python3 -m venv tutorial-env. This will create the tutorial-env directory. So virtual environment is a self-contained directory tree that contains a Python installation for a particular version of Python, plus a number of additional packages.

Commands to work with virtual environment:

  • python3 -m venv tutorial-env - create virtual environment

  • source tutorial-env/bin/activate - activate virtual environment on Unix or MacOS

  • tutorial-env\Scripts\activate - activate virtual environment on Windows

  • deactivate - to deactivate virtual environment

Python Virtual environment

Jupyter Notebook

Jupyter Notebook is an open-source web application that allows you to create and share documents that contain live code, equations, visualizations and narrative text.

Official website

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