from flask import Flask,render_template,flash,get_flashed_messages

app = Flask(__name__)
app.secret_key=("21h3i2o1")

@app.route('/x1')
def index1():
    flash(username)
    print(get_flashed_messages())  # 只会出现一次 马上就会显示
    return index1


@app.route(/x2 index2():
    print(get_flashed_messages())
    index2"


if __name__ == __main__:
    app.run(debug=True)