Misbehavior of KeyboardInterrupt/EOFError and `input` on Windows

[op200]

Bug report

Bug description:

import sys
from http.server import BaseHTTPRequestHandler, HTTPServer
from typing import NoReturn


def run_server() -> None:
    httpd = HTTPServer(("", 0), BaseHTTPRequestHandler)

    print("Starting service")
    try:
        httpd.serve_forever()
    except KeyboardInterrupt:
        print("Service stopped by ^C")
    finally:
        httpd.shutdown()
        httpd.server_close()


def run() -> NoReturn:
    print(f"Python: v{sys.version}")

    while True:
        try:
            input("input>")
        except KeyboardInterrupt:
            print("^C")
            continue
        except EOFError:
            print("Manually force exit")
            sys.exit()

        run_server()


if __name__ == "__main__":
    run()

I'm not sure if it's a bug

Expected

• When input, ^C can cancel current input and enter the next cycle
• When server, ^C can close server and enter the next cycle
• ^Z to exit (print("Manually force exit"))

Factual

• Enter to open server -> type ^C to close server -> type ^C
  • When py xxx.py, print("Manually force exit")
  • When pdb, \.vscode\extensions\ms-python.debugpy-2025.14.1-win32-x64\bundled\libs\debugpy\_vendored\pydevd\_pydevd_sys_monitoring\_pydevd_sys_monitoring.py", line 873 KeyboardInterrupt

CPython versions tested on:

3.14

Operating systems tested on:

Windows

[picnixz]

I don't understand. What is the exact traceback? please provide a screenshot or a recording. Is it the difference bewteen running the script with pdb vs without?

[picnixz]

Also,

.vscode\extensions\ms-python.debugpy-2025.14.1-win32-x64\bundled\libs\debugpy_vendored\pydevd_pydevd_sys_monitoring_pydevd_sys_monitoring.py",

I'm not entirely sure it's actually part of the standard library. It looks like a VS code issue here.

[op200]

run python this_file.py

1. press the key Enter to open server
2. ^C to close server
3. ^C, then it will run the line print("Manually force exit"). I don't understand why EOFError appears at this time, why isn't it KeyboardInterrupt

[yihong0618]

do you run this in VS Code terminal?
VS Code change and hack something, can you use a normal terminal to reproduce this?

[op200]

I can reproduce this issue in CMD and windows terminal (WIndows 10 & 11)

Only run python thisfile.py, then press the button in the above way (Enter -> ^C -> ^C)

[picnixz]

cc @zooba

[zooba]

Maybe KeyboardInterrupt isn't reset properly after it's handled? I know we have a bit of weirdness here to try and make it fit into the POSIX model, so it's entirely possible that it can't be triggered twice normally from the same console.

EOFError is what you normally get from a cancelled input(), so if we ignore injecting KeyboardInterrupt the second time, then this makes sense.