[BUG] color codes in windows console

Describe the bug

Color/format codes in console are literally printed.

To Reproduce

Use a simple fastapi setup like your readme example.

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}

Expected behavior

I figured out that this can be fixed by using os.system("cls") on top of your main.py

Screenshots

Expected with os.system("cls"):

Environment

• OS: Windows 10
• FastAPI Version 0.45.0
• Python version 3.8

Additional context

I do not think adding a raw os.system("cls") should be the right solution for a library. However, I do not know another way to fix the issue. On Ubuntu18.04 everything works as expected. Could be a problem with my windows machine. If this is a problem with my local machine, I am sorry. Also I know that I should post this on the uvicorn repo instead. But I figured that you should mention this as long as the bug exists.

[Jarmos-san]

This is a fairly common bug with non-ANSI-aware terminal(s). There’re similar reports even with Poetry (check this thread #1887 & if you search enough you might come across many other like these).

And also, to be honest it definitely isn’t a FastAPI related issue either. Not to forget how trivial & non-blocking this issue is. And if the guys at uvicorn are inclined they might want to look into this issue. With that in mind, I think it’s safe to close the issue.

Developing on Windows has never been better. You got WSL, Windows Terminal & many other CLI stuff to use. Take a look at the screenshot below, it’s a breeze working with the new Windows Terminal & it’s only gettting over time.

So my suggestions?

You don’t have to migrate to a Unix environment just for a “good” CLI. Windows 10 is fine, just use Powershell (or WSL) with the new Windows Terminal, more so if you’re a developer. This opinion is from someone who uses Ubuntu while on-the-go & Windows 10 on a desktop environment.

[zaanposni]

Hello @tiangolo,

I also grew up a bit and now use Linux for development 😄. However, I wanted to report this problem because it still exists. I’ve learned my part and think that using cmd.exe shouldn’t support everyone in their library.

How should we proceed? The problem still persists, although I would never expect anyone to fix it as it is very banal.