Python 教程

Check Python Installation

python3 --version

Install pip

Debian/Ubuntu:

sudo apt update  
sudo apt install python3-pip  


centos
sudo dnf install python3-pip -y

For macOS

brew install python

// This will install the latest version of Python along with pip.

python version management tools -- Pyenv

Install Pyenv on CentOS 9

curl https://pyenv.run | bash

Use Pyenv

// Install Python 3.10
pyenv install 3.10.13


# Set Python 3.10 as default
pyenv global 3.10.13

# Set local version for current directory
pyenv local 3.10.13


// Check current version:
pyenv versions
python --version


# List all available Python versions
pyenv install --list

# Uninstall a version
pyenv uninstall 3.10.13

# Show current version
pyenv version

Upgrade pip

python3 -m pip install --upgrade pip

install packages for requirements.txt

pip install -r requirements.txt

如果安装了python3，使用pip时报错：
zsh: command not found: pip

可以尝试
pip3 install -r requirements.txt

create a new virtual environment in Python

Open your command prompt or terminal.
Navigate to the directory where you want to create the virtual environment.
Run the following command to create a new virtual environment

python -m venv myenv

//Replace "myenv" with the name you want to give for your virtual environment.

python -m venv venv

Activate the virtual environment by running the activate script in the Scripts directory:

source myenv/bin/activate (Linux/Mac) 
myenv\Scripts\activate (Windows)

To exit the virtual environment, you can run the command:

deactivate

fastAPI

// 开发环境启动
fastapi dev main.py

// 生产环境启动
uvicorn main:app --host 0.0.0.0 --port 80

main: the file main.py (the Python "module").
app: the object created inside of main.py with the line app = FastAPI().

//  生产环境启动 in "daemon" mode (i.e., as a background process)
nohup uvicorn main:app --host 0.0.0.0 --port 9000 > /dev/null 2>&1 &

Poetry

Poetry 是一个用于管理 Python 项目的依赖和构建过程的工具。它简化了包管理和虚拟环境的创建，让开发者更容易管理项目的依赖关系。

Install Poetry Using Official Script

curl -sSL https://install.python-poetry.org | python3 -

You can test that everything is set up by executing

poetry --version

Add Poetry to PATH

如果是上述脚本安装的，通常不用这一步，会自动加到path里 If Poetry is not found after installation, add it to your PATH manually:

export PATH="$HOME/.local/bin:$PATH"

To make this change permanent, add it to your shell configuration file:

echo 'export PATH="$HOME/.local/bin:$PATH"' >> ~/.bashrc
source ~/.bashrc

// Use ~/.zshrc instead of ~/.bashrc if you're using zsh