from flask import Flask, request, render_template

app = Flask(__name__)

@app.route('/', methods=['GET', 'POST'])
def home():
    return render_template("home.html")

@app.route('/signin', methods=['GET'])
def signin_form():
    return render_template('form.html')

@app.route('/signin', methods=['POST'])
def signin():
    username = request.form['username']
    password = request.form['password']
    if username == 'admin' and password == 'password':
        return render_template("sign-ok.html", username = username)
    render_template('form.html', message = 'bad username or password', username = username)

if __name__ == '__main__':
    app.run()

想问下，最后的__name__是哪里的啊？为什么要等于'__main__'