Title: You can’t use input() inside a Flask route (EOFError). Use HTTP request data instead.

The error EOFError('EOF when reading a line') happens because Flask routes run inside a WSGI worker without an interactive terminal (stdin). input() tries to read from stdin, but there’s no TTY in an HTTP request context, so it immediately hits EOF. Even in debug, blocking on input() would stall the worker and break concurrency.

Don’t read from the server console in a route. Get user input from the HTTP request.

Use one of these patterns:

HTML form (POST)

from flask import Flask, request, render_template_string

app = Flask(name)

form_html = """

<form method="post"> <input name="username" placeholder="Username"> <button type="submit">Send</button> </form> """

@app.route("/ask", methods=["GET", "POST"])

def ask():

if request.method == "POST":

username = request.form.get("username")

return f"Hello, {username}!"

return render_template_string(form_html)

JSON API (AJAX/fetch)

from flask import Flask, request, jsonify

app = Flask(name)

@app.route("/api/answer", methods=["POST"])

def api_answer():

data = request.get_json(silent=True) or {}

answer = data.get("answer")

if not answer:

return jsonify(error="missing 'answer'"), 400

return jsonify(ok=True, echoed=answer)

Client:

fetch("/api/answer", {

method: "POST",

headers: {"Content-Type": "application/json"},

body: JSON.stringify({answer: "hello"})

})

Query parameters (GET)

from flask import Flask, request

app = Flask(name)

@app.route("/greet")

def greet():

name = request.args.get("name", "world")

return f"Hello, {name}!"

Call: /greet?name=Alice

Path parameters

from flask import Flask

app = Flask(name)

@app.route("/user/<username>")

def user(username):

return f"Hello, {username}!"

If you truly need interactive, real-time input, use WebSockets (e.g., Flask-SocketIO) to exchange messages with the browser. If you want terminal prompts, build a separate CLI script and don’t call input() inside Flask routes.