python - 《Flask Web开发》第六章在程序中集成发送电子邮件功能 raise TemplateNotFound(template)-Soal Jawab Rangkaian PHP Cina

修改hello.py代码不知道为什么会出现raise TemplateNotFound(template)
TemplateNotFound: 500.html这个错误

hello.py

import os
from flask import Flask, render_template, session, redirect, url_for, flash
from flask_script import Shell, Manager
from flask_bootstrap import Bootstrap
from flask_moment import Moment
from flask_wtf import Form
from wtforms import StringField, SubmitField
from wtforms.validators import Required
from flask_sqlalchemy import SQLAlchemy
from flask_migrate import Migrate, MigrateCommand
from flask_mail import Mail, Message

basedir = os.path.abspath(os.path.dirname(__file__))

app = Flask(__name__)
app.config['SECRET_KEY'] = 'zhao xiufeng'
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///' + os.path.join(basedir, 'data.sqlite')
app.config['SQLALCHEMY_COMMIT_ON_TEARDOWN'] = True
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = True
app.config['MAIL_SERVER'] = 'smtp.163.com'  #'smtp.qq.com'   
app.config['MAIL_PORT'] = '465'
app.config['MAIL_USE_SSL'] = True
app.config['MAIL_USERNAME'] = os.environ.get('MAIL_USERNAME')
app.config['MAIL_PASSWORD'] = os.environ.get('MAIL_PASSWORD')
app.config['FLASKY_MAIL_SUBJECT_PREFIX'] = '[Flasky]'
app.config['FLASKY_MAIL_SENDER'] = 'Flasky Admin <werswee@163.com>'
app.config['FLASKY_ADMIN'] = os.environ.get('FLASKY_ADMIN')

manager = Manager(app)
bootstrap = Bootstrap(app)
moment = Moment(app)
db = SQLAlchemy(app)
migrate = Migrate(app,db)
mail = Mail(app) 

class Role(db.Model):
    __tablename__ = 'roles'
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(64), unique=True)

    users = db.relationship('User', backref='role', lazy='dynamic')

    def __repr__(self):
        return '<Role %r>' % self.name

class User(db.Model):
    __tablename__ = 'Users'
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(64), unique=True, index=True)

    role_id = db.Column(db.Integer, db.ForeignKey('roles.id'))

    def __repr__(self):
        return '<User %r>' % self.username

def send_email(to, subject, template, **kwargs):
    msg = Message(app.config['FLASKY_MAIL_SUBJECT_PREFIX']  + subject, sender=app.config['FLASKY_MAIL_SENDER'], recipients=[to])
    msg.body = render_template(template + '.txt', **kwargs)
    msg.html = render_template(template + '.html', **kwargs)
    mail.send(msg)

class NameForm(Form):
    name = StringField('What is your name?', validators=[Required()])
    submit = SubmitField('Submit')


def make_shell_context():
    return dict(app=app, db=db, User=User, Role=Role)
manager.add_command("shell", Shell(make_context=make_shell_context))
manager.add_command('db', MigrateCommand)  

@app.route('/', methods=['GET','POST'])
def index():
    form = NameForm()
    if form.validate_on_submit():
        user = User.query.filter_by(username=form.name.data).first()
        if user is None:
            user = User(username = form.name.data)
            db.session.add(user)
            session['known'] = False
            if app.config['FLASKY_ADMIN']:
                send_email(app.config['FLASKY_ADMIN'], 'New User', 'mail/new_user', user=user)
        else:
            session['known'] = True
        session['name'] = form.name.data
        #form.name.data = ''
        return redirect(url_for('index'))
    return render_template('index.html', form = form, 
    name = session.get('name'), known = session.get('known', False))

@app.route('/user/<name>')
def user(name):
    return render_template('user.html', name=name)

@app.errorhandler(404)
def page_not_found(e):
    return render_template('404.html'),404

@app.errorhandler(500)
def internal_server_error(e):
    return render_template('500.html'),500

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

报错

hello.py:74: FlaskWTFDeprecationWarning: "flask_wtf.Form" has been renamed to "FlaskForm" and will be removed in 1.0.
  form = NameForm()
127.0.0.1 - - [05/Feb/2017 00:16:38] "GET / HTTP/1.1" 200 -
hello.py:74: FlaskWTFDeprecationWarning: "flask_wtf.Form" has been renamed to "FlaskForm" and will be removed in 1.0.
  form = NameForm()
[2017-02-05 00:16:42,523] ERROR in app: Exception on / [POST]
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1982, in wsgi_app
    response = self.full_dispatch_request()
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1614, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1517, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1612, in full_dispatch_request
    rv = self.dispatch_request()
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1598, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "hello.py", line 76, in index
    user = User.query.filter_by(username=form.name.data).first()
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/query.py", line 2697, in first
    ret = list(self[0:1])
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/query.py", line 2489, in __getitem__
    return list(res)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/query.py", line 2797, in __iter__
    return self._execute_and_instances(context)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/query.py", line 2820, in _execute_and_instances
    result = conn.execute(querycontext.statement, self._params)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 945, in execute
    return meth(self, multiparams, params)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/sql/elements.py", line 263, in _execute_on_connection
    return connection._execute_clauseelement(self, multiparams, params)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1053, in _execute_clauseelement
    compiled_sql, distilled_params
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1189, in _execute_context
    context)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1393, in _handle_dbapi_exception
    exc_info
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/util/compat.py", line 202, in raise_from_cause
    reraise(type(exception), exception, tb=exc_tb, cause=cause)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1182, in _execute_context
    context)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/default.py", line 469, in do_execute
    cursor.execute(statement, parameters)
OperationalError: (sqlite3.OperationalError) no such table: Users [SQL: u'SELECT "Users".id AS "Users_id", "Users".username AS "Users_username", "Users".role_id AS "Users_role_id" \nFROM "Users" \nWHERE "Users".username = ?\n LIMIT ? OFFSET ?'] [parameters: (u'111111', 1, 0)]
127.0.0.1 - - [05/Feb/2017 00:16:42] "POST / HTTP/1.1" 500 -
Error on request:
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/werkzeug/serving.py", line 193, in run_wsgi
    execute(self.server.app)
  File "/usr/local/lib/python2.7/dist-packages/werkzeug/serving.py", line 181, in execute
    application_iter = app(environ, start_response)
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1994, in __call__
    return self.wsgi_app(environ, start_response)
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1985, in wsgi_app
    response = self.handle_exception(e)
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1547, in handle_exception
    return self.finalize_request(handler(e), from_error_handler=True)
  File "/home/fang/app/hello.py", line 101, in internal_server_error
    return render_template('500.html'),500
  File "/usr/local/lib/python2.7/dist-packages/flask/templating.py", line 133, in render_template
    return _render(ctx.app.jinja_env.get_or_select_template(template_name_or_list),
  File "/usr/local/lib/python2.7/dist-packages/jinja2/environment.py", line 851, in get_or_select_template
    return self.get_template(template_name_or_list, parent, globals)
  File "/usr/local/lib/python2.7/dist-packages/jinja2/environment.py", line 812, in get_template
    return self._load_template(name, self.make_globals(globals))
  File "/usr/local/lib/python2.7/dist-packages/jinja2/environment.py", line 774, in _load_template
    cache_key = self.loader.get_source(self, name)[1]
  File "/usr/local/lib/python2.7/dist-packages/flask/templating.py", line 57, in get_source
    return self._get_source_fast(environment, template)
  File "/usr/local/lib/python2.7/dist-packages/flask/templating.py", line 85, in _get_source_fast
    raise TemplateNotFound(template)
TemplateNotFound: 500.html

幻境变量什么的都设置好的，也是对的
上一节在Python shell中发送电子邮件都是成功的。。。
目录：
.
├── data.sqlite
├── hello.py
├── hello.pyc
├── migrations
│   ├── alembic.ini
│   ├── env.py
│   ├── env.pyc
│   ├── README
│   ├── script.py.mako
│   └── versions
├── static
│   └── favicon.ico
├── templates
│   ├── 404.html
│   ├── base.html
│   ├── index.html
│   ├── mail
│   │   ├── new_user.html
│   │   └── new_user.txt
│   └── user.html