⚒ & 🌐 🔢

📚 💼 👆 🈸 💪 💪 🔢 ⚒ ⚖️ 📳, 🖼 ㊙ 🔑, 💽 🎓, 🎓 📧 🐕‍🦺, ♒️.

🏆 👫 ⚒ 🔢 (💪 🔀), 💖 💽 📛. & 📚 💪 🚿, 💖 ㊙.

👉 🤔 ⚫️ ⚠ 🚚 👫 🌐 🔢 👈 ✍ 🈸.

🌐 🔢

Tip

🚥 👆 ⏪ 💭 ⚫️❔ "🌐 🔢" & ❔ ⚙️ 👫, 💭 🆓 🚶 ⏭ 📄 🔛.

🌐 🔢 (💭 "🇨🇻 {") 🔢 👈 🖖 🏞 🐍 📟, 🏃‍♂ ⚙️, & 💪 ✍ 👆 🐍 📟 (⚖️ 🎏 📋 👍).

👆 💪 ✍ & ⚙️ 🌐 🔢 🐚, 🍵 💆‍♂ 🐍:

💾, 🇸🇻, 🚪 🎉🚪 📋

// You could create an env var MY_NAME with
$ export MY_NAME="Wade Wilson"

// Then you could use it with other programs, like
$ echo "Hello $MY_NAME"

Hello Wade Wilson

// Create an env var MY_NAME
$ $Env:MY_NAME = "Wade Wilson"

// Use it with other programs, like
$ echo "Hello $Env:MY_NAME"

Hello Wade Wilson

✍ 🇨🇻 {🐍

👆 💪 ✍ 🌐 🔢 🏞 🐍, 📶 (⚖️ ⏮️ 🙆 🎏 👩‍🔬), & ⤴️ ✍ 👫 🐍.

🖼 👆 💪 ✔️ 📁 main.py ⏮️:

import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")

Tip

🥈 ❌ os.getenv() 🔢 💲 📨.

🚥 🚫 🚚, ⚫️ None 🔢, 📥 👥 🚚 "World" 🔢 💲 ⚙️.

⤴️ 👆 💪 🤙 👈 🐍 📋:

// Here we don't set the env var yet
$ python main.py

// As we didn't set the env var, we get the default value

Hello World from Python

// But if we create an environment variable first
$ export MY_NAME="Wade Wilson"

// And then call the program again
$ python main.py

// Now it can read the environment variable

Hello Wade Wilson from Python

🌐 🔢 💪 ⚒ 🏞 📟, ✋️ 💪 ✍ 📟, & 🚫 ✔️ 🏪 (💕 git) ⏮️ 🎂 📁, ⚫️ ⚠ ⚙️ 👫 📳 ⚖️ ⚒.

👆 💪 ✍ 🌐 🔢 🕴 🎯 📋 👼, 👈 🕴 💪 👈 📋, & 🕴 🚮 📐.

👈, ✍ ⚫️ ▶️️ ⏭ 📋 ⚫️, 🔛 🎏 ⏸:

// Create an env var MY_NAME in line for this program call
$ MY_NAME="Wade Wilson" python main.py

// Now it can read the environment variable

Hello Wade Wilson from Python

// The env var no longer exists afterwards
$ python main.py

Hello World from Python

Tip

👆 💪 ✍ 🌅 🔃 ⚫️ 1️⃣2️⃣-⚖ 📱: 📁.

🆎 & 🔬

👫 🌐 🔢 💪 🕴 🍵 ✍ 🎻, 👫 🔢 🐍 & ✔️ 🔗 ⏮️ 🎏 📋 & 🎂 ⚙️ (& ⏮️ 🎏 🏃‍♂ ⚙️, 💾, 🚪, 🇸🇻).

👈 ⛓ 👈 🙆 💲 ✍ 🐍 ⚪️➡️ 🌐 🔢 🔜 str, & 🙆 🛠️ 🎏 🆎 ⚖️ 🔬 ✔️ 🔨 📟.

Pydantic Settings

👐, Pydantic 🚚 👑 🚙 🍵 👫 ⚒ 👟 ⚪️➡️ 🌐 🔢 ⏮️ Pydantic: ⚒ 🧾.

✍ Settings 🎚

🗄 BaseSettings ⚪️➡️ Pydantic & ✍ 🎧-🎓, 📶 🌅 💖 ⏮️ Pydantic 🏷.

🎏 🌌 ⏮️ Pydantic 🏷, 👆 📣 🎓 🔢 ⏮️ 🆎 ✍, & 🎲 🔢 💲.

👆 💪 ⚙️ 🌐 🎏 🔬 ⚒ & 🧰 👆 ⚙️ Pydantic 🏷, 💖 🎏 📊 🆎 & 🌖 🔬 ⏮️ Field().

from fastapi import FastAPI
from pydantic_settings import BaseSettings


class Settings(BaseSettings):
    app_name: str = "Awesome API"
    admin_email: str
    items_per_user: int = 50


settings = Settings()
app = FastAPI()


@app.get("/info")
async def info():
    return {
        "app_name": settings.app_name,
        "admin_email": settings.admin_email,
        "items_per_user": settings.items_per_user,
    }

Tip

🚥 👆 💚 🕳 ⏩ 📁 & 📋, 🚫 ⚙️ 👉 🖼, ⚙️ 🏁 1️⃣ 🔛.

⤴️, 🕐❔ 👆 ✍ 👐 👈 Settings 🎓 (👉 💼, settings 🎚), Pydantic 🔜 ✍ 🌐 🔢 💼-😛 🌌,, ↖-💼 🔢 APP_NAME 🔜 ✍ 🔢 app_name.

⏭ ⚫️ 🔜 🗜 & ✔ 💽. , 🕐❔ 👆 ⚙️ 👈 settings 🎚, 👆 🔜 ✔️ 📊 🆎 👆 📣 (✅ items_per_user 🔜 int).

⚙️ settings

⤴️ 👆 💪 ⚙️ 🆕 settings 🎚 👆 🈸:

from fastapi import FastAPI
from pydantic_settings import BaseSettings


class Settings(BaseSettings):
    app_name: str = "Awesome API"
    admin_email: str
    items_per_user: int = 50


settings = Settings()
app = FastAPI()


@app.get("/info")
async def info():
    return {
        "app_name": settings.app_name,
        "admin_email": settings.admin_email,
        "items_per_user": settings.items_per_user,
    }

🏃 💽

⏭, 👆 🔜 🏃 💽 🚶‍♀️ 📳 🌐 🔢, 🖼 👆 💪 ⚒ ADMIN_EMAIL & APP_NAME ⏮️:

$ ADMIN_EMAIL="deadpool@example.com" APP_NAME="ChimichangApp" uvicorn main:app

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)

Tip

⚒ 💗 🇨🇻 {👁 📋 🎏 👫 ⏮️ 🚀, & 🚮 👫 🌐 ⏭ 📋.

& ⤴️ admin_email ⚒ 🔜 ⚒ "deadpool@example.com".

app_name 🔜 "ChimichangApp".

& items_per_user 🔜 🚧 🚮 🔢 💲 50.

⚒ ➕1️⃣ 🕹

👆 💪 🚮 👈 ⚒ ➕1️⃣ 🕹 📁 👆 👀 🦏 🈸 - 💗 📁.

🖼, 👆 💪 ✔️ 📁 config.py ⏮️:

from pydantic_settings import BaseSettings


class Settings(BaseSettings):
    app_name: str = "Awesome API"
    admin_email: str
    items_per_user: int = 50


settings = Settings()

& ⤴️ ⚙️ ⚫️ 📁 main.py:

from fastapi import FastAPI

from .config import settings

app = FastAPI()


@app.get("/info")
async def info():
    return {
        "app_name": settings.app_name,
        "admin_email": settings.admin_email,
        "items_per_user": settings.items_per_user,
    }

Tip

👆 🔜 💪 📁 __init__.py 👆 👀 🔛 🦏 🈸 - 💗 📁.

⚒ 🔗

🍾 ⚫️ 5️⃣📆 ⚠ 🚚 ⚒ ⚪️➡️ 🔗, ↩️ ✔️ 🌐 🎚 ⏮️ settings 👈 ⚙️ 🌐.

👉 💪 ✴️ ⚠ ⏮️ 🔬, ⚫️ 📶 ⏩ 🔐 🔗 ⏮️ 👆 👍 🛃 ⚒.

📁 📁

👟 ⚪️➡️ ⏮️ 🖼, 👆 config.py 📁 💪 👀 💖:

from pydantic_settings import BaseSettings


class Settings(BaseSettings):
    app_name: str = "Awesome API"
    admin_email: str
    items_per_user: int = 50

👀 👈 🔜 👥 🚫 ✍ 🔢 👐 settings = Settings().

👑 📱 📁

🔜 👥 ✍ 🔗 👈 📨 🆕 config.Settings().

from functools import lru_cache

from fastapi import Depends, FastAPI

from .config import Settings

app = FastAPI()


@lru_cache
def get_settings():
    return Settings()


@app.get("/info")
async def info(settings: Settings = Depends(get_settings)):
    return {
        "app_name": settings.app_name,
        "admin_email": settings.admin_email,
        "items_per_user": settings.items_per_user,
    }

Tip

👥 🔜 🔬 @lru_cache 🍖.

🔜 👆 💪 🤔 get_settings() 😐 🔢.

& ⤴️ 👥 💪 🚚 ⚫️ ⚪️➡️ ➡ 🛠️ 🔢 🔗 & ⚙️ ⚫️ 🙆 👥 💪 ⚫️.

from functools import lru_cache

from fastapi import Depends, FastAPI

from .config import Settings

app = FastAPI()


@lru_cache
def get_settings():
    return Settings()


@app.get("/info")
async def info(settings: Settings = Depends(get_settings)):
    return {
        "app_name": settings.app_name,
        "admin_email": settings.admin_email,
        "items_per_user": settings.items_per_user,
    }

⚒ & 🔬

⤴️ ⚫️ 🔜 📶 ⏩ 🚚 🎏 ⚒ 🎚 ⏮️ 🔬 🏗 🔗 🔐 get_settings:

from fastapi.testclient import TestClient

from .config import Settings
from .main import app, get_settings

client = TestClient(app)


def get_settings_override():
    return Settings(admin_email="testing_admin@example.com")


app.dependency_overrides[get_settings] = get_settings_override


def test_app():
    response = client.get("/info")
    data = response.json()
    assert data == {
        "app_name": "Awesome API",
        "admin_email": "testing_admin@example.com",
        "items_per_user": 50,
    }

🔗 🔐 👥 ⚒ 🆕 💲 admin_email 🕐❔ 🏗 🆕 Settings 🎚, & ⤴️ 👥 📨 👈 🆕 🎚.

⤴️ 👥 💪 💯 👈 ⚫️ ⚙️.

👂 .env 📁

🚥 👆 ✔️ 📚 ⚒ 👈 🎲 🔀 📚, 🎲 🎏 🌐, ⚫️ 5️⃣📆 ⚠ 🚮 👫 🔛 📁 & ⤴️ ✍ 👫 ⚪️➡️ ⚫️ 🚥 👫 🌐 🔢.

👉 💡 ⚠ 🥃 👈 ⚫️ ✔️ 📛, 👫 🌐 🔢 🛎 🥉 📁 .env, & 📁 🤙 "🇨🇻".

Tip

📁 ▶️ ⏮️ ❣ (.) 🕵‍♂ 📁 🖥-💖 ⚙️, 💖 💾 & 🇸🇻.

✋️ 🇨🇻 📁 🚫 🤙 ✔️ ✔️ 👈 ☑ 📁.

Pydantic ✔️ 🐕‍🦺 👂 ⚪️➡️ 👉 🆎 📁 ⚙️ 🔢 🗃. 👆 💪 ✍ 🌖 Pydantic ⚒: 🇨🇻 (.🇨🇻) 🐕‍🦺.

Tip

👉 👷, 👆 💪 pip install python-dotenv.

.env 📁

👆 💪 ✔️ .env 📁 ⏮️:

ADMIN_EMAIL="deadpool@example.com"
APP_NAME="ChimichangApp"

✍ ⚒ ⚪️➡️ .env

& ⤴️ ℹ 👆 config.py ⏮️:

from pydantic_settings import BaseSettings


class Settings(BaseSettings):
    app_name: str = "Awesome API"
    admin_email: str
    items_per_user: int = 50

    class Config:
        env_file = ".env"

📥 👥 ✍ 🎓 Config 🔘 👆 Pydantic Settings 🎓, & ⚒ env_file 📁 ⏮️ 🇨🇻 📁 👥 💚 ⚙️.

Tip

Config 🎓 ⚙️ Pydantic 📳. 👆 💪 ✍ 🌖 Pydantic 🏷 📁

🏗 Settings 🕴 🕐 ⏮️ lru_cache

👂 📁 ⚪️➡️ 💾 🛎 ⚠ (🐌) 🛠️, 👆 🎲 💚 ⚫️ 🕴 🕐 & ⤴️ 🏤-⚙️ 🎏 ⚒ 🎚, ↩️ 👂 ⚫️ 🔠 📨.

✋️ 🔠 🕰 👥:

Settings()

🆕 Settings 🎚 🔜 ✍, & 🏗 ⚫️ 🔜 ✍ .env 📁 🔄.

🚥 🔗 🔢 💖:

def get_settings():
    return Settings()

👥 🔜 ✍ 👈 🎚 🔠 📨, & 👥 🔜 👂 .env 📁 🔠 📨. 👶 👶

✋️ 👥 ⚙️ @lru_cache 👨‍🎨 🔛 🔝, Settings 🎚 🔜 ✍ 🕴 🕐, 🥇 🕰 ⚫️ 🤙. 👶 👶

from functools import lru_cache

from fastapi import Depends, FastAPI

from . import config

app = FastAPI()


@lru_cache
def get_settings():
    return config.Settings()


@app.get("/info")
async def info(settings: config.Settings = Depends(get_settings)):
    return {
        "app_name": settings.app_name,
        "admin_email": settings.admin_email,
        "items_per_user": settings.items_per_user,
    }

⤴️ 🙆 🏁 🤙 get_settings() 🔗 ⏭ 📨, ↩️ 🛠️ 🔗 📟 get_settings() & 🏗 🆕 Settings 🎚, ⚫️ 🔜 📨 🎏 🎚 👈 📨 🔛 🥇 🤙, 🔄 & 🔄.

lru_cache 📡 ℹ

@lru_cache 🔀 🔢 ⚫️ 🎀 📨 🎏 💲 👈 📨 🥇 🕰, ↩️ 💻 ⚫️ 🔄, 🛠️ 📟 🔢 🔠 🕰.

, 🔢 🔛 ⚫️ 🔜 🛠️ 🕐 🔠 🌀 ❌. & ⤴️ 💲 📨 🔠 👈 🌀 ❌ 🔜 ⚙️ 🔄 & 🔄 🕐❔ 🔢 🤙 ⏮️ ⚫️❔ 🎏 🌀 ❌.

🖼, 🚥 👆 ✔️ 🔢:

@lru_cache
def say_hi(name: str, salutation: str = "Ms."):
    return f"Hello {salutation} {name}"

👆 📋 💪 🛠️ 💖 👉:

sequenceDiagram

participant code as Code
participant function as say_hi()
participant execute as Execute function

    rect rgba(0, 255, 0, .1)
        code ->> function: say_hi(name="Camila")
        function ->> execute: execute function code
        execute ->> code: return the result
    end

    rect rgba(0, 255, 255, .1)
        code ->> function: say_hi(name="Camila")
        function ->> code: return stored result
    end

    rect rgba(0, 255, 0, .1)
        code ->> function: say_hi(name="Rick")
        function ->> execute: execute function code
        execute ->> code: return the result
    end

    rect rgba(0, 255, 0, .1)
        code ->> function: say_hi(name="Rick", salutation="Mr.")
        function ->> execute: execute function code
        execute ->> code: return the result
    end

    rect rgba(0, 255, 255, .1)
        code ->> function: say_hi(name="Rick")
        function ->> code: return stored result
    end

    rect rgba(0, 255, 255, .1)
        code ->> function: say_hi(name="Camila")
        function ->> code: return stored result
    end

💼 👆 🔗 get_settings(), 🔢 🚫 ✊ 🙆 ❌, ⚫️ 🕧 📨 🎏 💲.

👈 🌌, ⚫️ 🎭 🌖 🚥 ⚫️ 🌐 🔢. ✋️ ⚫️ ⚙️ 🔗 🔢, ⤴️ 👥 💪 🔐 ⚫️ 💪 🔬.

@lru_cache 🍕 functools ❔ 🍕 🐍 🐩 🗃, 👆 💪 ✍ 🌅 🔃 ⚫️ 🐍 🩺 @lru_cache.

🌃

👆 💪 ⚙️ Pydantic ⚒ 🍵 ⚒ ⚖️ 📳 👆 🈸, ⏮️ 🌐 🏋️ Pydantic 🏷.

• ⚙️ 🔗 👆 💪 📉 🔬.
• 👆 💪 ⚙️ .env 📁 ⏮️ ⚫️.
• ⚙️ @lru_cache ➡️ 👆 ❎ 👂 🇨🇻 📁 🔄 & 🔄 🔠 📨, ⏪ 🤝 👆 🔐 ⚫️ ⏮️ 🔬.