Flask Blueprint (Blueprint) Simple test example Run unsuccessful: Registration is not the right time __flask

Wrote a simple blueprint Test example ran after the browser access failed, the code is as follows:

Flask, Blueprint

bp = Blueprint (' admin ', __name__)

app = Flask (__name__)
App.register_blueprint (BP)

@bp. Route ('/')
Index ():
    ' 
     ' __name__ = ' __main__ ':
    app.run ()

After various tests found that the timing of the registration blueprint is not correct, should be set up after the Blueprint Route registration Blueprint, code changes as follows:

Flask, Blueprint

bp = Blueprint (' admin ', __name__)

@bp. Route ('/')
Index ():
    ' < H1>root testAbout ():
    ' __name__ = = ' __main__ ' :
    App.run ()