Python Tpis

Virtual Env

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Plain Python Method

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Creat

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Some tipical code 👇

# creat a virtual env named "your_env_name"
python -m venv your_env_name

# assign the version of python, make sure your python in default direction
python -m venv your_env_name --python=python3.11

# simply list the absolute direction of python, simple and efficient
D:/PythonPython311/python.exe -m venv your_env_name

More parameters you may need for a customized virtual env. 🤔

Activate

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The virtual env is defaulted not active. In the direction your_env_name/Scripts/ will be a file named activate. Run it with your cmd.

# activate virtual env
your_env_name/Scripts/activate

Poetry

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Poetry is a Python package management tool that started development in February 2018, according to its changelog. It’s not exactly a new tool, but it has become quite popular in recent years 💫.

The key highlights promoted by its official documentation include:

• More detailed and comprehensive analysis of third-party dependencies
• Automated virtual environment creation
• More intuitive and user-friendly commands 🤔

Installation

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It’s straightforward: pip install poetry for global installation.

Global Configuration

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Poetry has some unique mechanisms that differ from tools like pip. You might need to set up some configurations, which can be done as follows:

# List all configurations
poetry config --list

# By default, Poetry creates virtual environments in a dedicated folder, not within the project directory
# Use the following command to create the virtual environment in the project directory
poetry config virtualenvs.in-project true

# Poetry will automatically create a virtual environment when one doesn't exist in the project
# To be sure, you can run this command
poetry config virtualenvs.create true

# Other settings can usually be left as default

Initialize a Project

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If you need to create a new project from scratch, you’ll want to create a project folder, navigate to it in your terminal, and then run:

poetry init

An interactive CLI will guide you through creating a new project, which will generate two key files for Poetry: pyproject.toml for managing dependencies, and poetry.lock to lock package versions, similar to pip’s requirements.txt. Those familiar with Node.js should find this concept quite familiar 😝.

If you’re working with someone else’s project, it will usually include those two files.

If you want a simple directory structure, you can use:

poetry new my-package

This will create a basic project structure like this:

my-package
├── pyproject.toml
├── README.md
├── my_package
│   └── __init__.py
└── tests
    └── __init__.py

For more complex needs, refer to the new Command documentation.

Create a Virtual Environment

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There are a few situations to consider here:

1. If you’re building your project from scratch:

poetry env use python # Default Python version you installed Poetry with

poetry env use python3.7 # Use the Python 3.7 version on your system

poetry env use 3.7 # A shortcut for the above

poetry env use /full/path/to/python # Use this if the above shortcuts don't work

2. If you’re working with someone else’s project:

There are two very similar commands. As shown in the comments, the official recommendation is to use sync, as it avoids installing any packages that aren’t tracked by poetry.lock, which may include unintended packages that the original developer added.

However, I personally recommend to use install. The sync command may result into some strange error: it may remove itself and causes the command line break out.🤔

# Automatically creates a virtual environment and installs all dependencies from pyproject.toml
poetry install

# Make sure virtualenvs.create is set to true
# Automatically creates a virtual environment, installs dependencies from poetry.lock and remove redundant package in pyproject.toml
poetry sync

To activate the virtual environment, use:

poetry shell

Add Packages

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Poetry lets you differentiate between packages needed in the production environment and those only required for development:

# Add a package to the production environment
poetry add your-package

# Add a package to the development environment
poetry add your-package -D

Update Packages

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poetry update # Automatically analyzes dependencies and updates all packages if necessary

poetry update your-package1 your-package2 # Only updates the specific packages you list

Remove Packages

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This is one of Poetry’s standout features: While pip installs the specified package and its third-party dependencies, it can’t remove these dependencies when you uninstall a package. Poetry, on the other hand, safely and completely removes the dependencies tied to a package without affecting others.

# Remove a package from the production environment
poetry remove your-package

# Remove a package from the development environment
poetry remove your-package -D

Show Dependencies

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poetry show --tree # Show the dependency tree of the packages in pyproject.toml

poetry show your-package --tree # Show the dependency tree for a specific package

Program Packaging

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We often need to share our Python programs. However, sharing the source code alone can be frustrating for users who aren’t familiar with coding, as it requires setting up a local environment to run the code. Therefore, program packaging comes in handy.

PyInstaller

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Installation is very simple, just like any other Python package: pip install pyinstaller. To use it, open the terminal in the target directory and run the command.

Features: Fast packaging speed; relatively large packaged files

Common command codes:

# Package the main.py file as a standalone executable; the command window is disabled when the executable runs
pyinstaller -F -w main.py

# Package the main.py file into a project folder; the command window is enabled when the executable runs
pyinstaller -D main.py

Nuitka

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Nuitka packages Python code into an executable (.exe). The underlying process first converts Python code to C code, then compiles the C code.

Features: Slow packaging speed; requires an additional C compiler (though automatic setup is possible, it can be strict on memory management, so may not be suitable for users with limited space); smaller packaged files (tested to be about one-tenth the size of PyInstaller’s output)

Installation command:

pip install -U nuitka

Common usage command:

# Package the main.py file into an exe file with link-time optimization, and remove temporary files after packaging
python -m nuitka --lto=yes --remove-output --onefile main.py

Reference

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• poetry related:
  • poetry 入门完全指南_poetry使用-CSDN博客, a detailed and first-hand blog.
  • Poetry, the official documents.