Python Flask 脚本在作为 .pyw 文件运行时自动关闭（包括解决方法）

Question

Problem

I've created a basic python script, using flask to render an HTML page. On Windows 10, the script works perfectly as a *.py file, but when run as a *.pyw file, the page is not rendered.

In Task Manager, instances of python are opened and closed within seconds after running the script as *.pyw .

---

Code

from flask import Flask, render_template

app = Flask(__name__)

@app.route("/")
def main():
    return render_template('index.html')

if __name__ == '__main__':
    app.run(debug=True, host="0.0.0.0", port=80)

---

Workaround

Run the *.py version with the following lines added to the code:

import ctypes
...
...
...
if __name__ == '__main__':
  cytypes.windll.user32.ShowWindow(ctypes.windll.kernel32.GetConsoleWindow(), 0)
  app.run(debug=True, host="0.0.0.0", port=80)

Code above hides the console, and starts the flask app successfully.

---

However, I am still interested in an explanation as to why the *.pyw method won't work, if anyone has an idea.

Answer 1

.pyw-files would ran on pythonw.exe rather than python.exe . The difference is, that pythonw.exe does not run in a console by default and runs asynchronous. This would mean that flask starts and runs in the background untill everything else terminates. Since you to not have anything else in your application, the programm ends directly.