framework'den geliyorsanız ve küçük bir performans kazancı (yaklaşık 100 nanosaniye) için  "def" ile *path fonksiyonu* tanımlamaya alışkınsanız, **FastAPI**'de tam tersi olacağını unutmayın. Bu durumlarda, *path fonksiyonu* <abbr title="Input/Output: disk okuma veya yazma, ağ iletişimleri.">G/Ç</abbr> engelleyen durum oluşturmadıkça "async def" kullanmak daha iyidir.

Yine de, her iki durumda da, **FastAPI**'nin önceki frameworkden [hala daha hızlı](index.md#performans){.internal-link target=_blank}...

🚥 👆 👟 ⚪️➡️ ➕1️⃣ 🔁 🛠️ 👈 🔨 🚫 👷 🌌 🔬 🔛 &amp; 👆 ⚙️ ⚖ 🙃 📊-🕴 *➡ 🛠️ 🔢* ⏮️ ✅ `def` 🤪 🎭 📈 (🔃 1️⃣0️⃣0️⃣ 💓), 🙏 🗒 👈 **FastAPI** ⭐ 🔜 🔄. 👫 💼, ⚫️ 👻 ⚙️ `async def` 🚥 👆 *➡ 🛠️ 🔢* ⚙️ 📟 👈 🎭 🚧 <abbr title="Input/Output: disk reading or writing, network communications.">👤/🅾</abbr>.

, 👯‍♂️ ⚠, 🤞 👈 **FastAPI** 🔜 [⏩](index.md#_15){.internal-link target=_blank} 🌘 (⚖️ 🌘 ⭐) 👆 ⏮️ 🛠️.

### 🔗

* the data from the client to be sent through the network
* the data sent by your program to be received by the client through the network
* the contents of a file in the disk to be read by the system and given to your program
* the contents your program gave to the system to be written to disk
* a remote API operation
* a database operation to finish
* a database query to return the results
* etc.

(aproximadamente 100 nanosegundos), ten en cuenta que en **FastAPI** el efecto sería bastante opuesto. En estos casos, es mejor usar `async def` a menos que tus *path operation functions* usen un código que realice el bloqueo <abbr title="Input/Output: disk reading or writing, network communications.">I/O</abbr>.

Aún así, en ambas situaciones, es probable que **FastAPI** sea [aún más rápido](index.md#rendimiento){.Internal-link target=_blank} que (o al menos comparable) a tu framework anterior....