old_contents: from flask import Flask, render_template, session, redirect, url_for
  from flask.ext.script import Manager
  from flask.ext.bootstrap import Bootstrap
  from flask.ext.moment import Moment
  from flask.ext.wtf import Form
  from wtforms import StringField, SubmitField
  from wtforms.validators import Required
  from datetime import datetime
  
  app = Flask(__name__)
  app.config[ 'SECRET_KEY' ] = 'hard to guess string'
  
  manager = Manager(app)
  bootstrap = Bootstrap(app)
  moment = Moment(app)
  
  class NameForm(Form):
      name = StringField('what\'s your name?', validators = [Required()] )
      submit = SubmitField('Submit')
  
  @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
  
  @app.route('/', method = ['GET', 'POST'])
  def index():
      form = NameForm()
      if from.validate_on_submit():
          session['name'] = form.name.data
          return redirect(url_for('index'))
      return render_template('index.html', form = form, name = session.get('name'))
  
  
  @app.route('/user/<name>')
  def user(name):
      return render_template('user.html', name=name)
  
  
  if __name__ == '__main__':
      manager.run()
  
new_contents: from flask import Flask, render_template, session, redirect, url_for
  from flask.ext.script import Manager
  from flask.ext.bootstrap import Bootstrap
  from flask.ext.moment import Moment
  from flask.ext.wtf import Form
  from wtforms import StringField, SubmitField
  from wtforms.validators import Required
  from datetime import datetime
  
  app = Flask(__name__)
  app.config[ 'SECRET_KEY' ] = 'hard to guess string'
  
  manager = Manager(app)
  bootstrap = Bootstrap(app)
  moment = Moment(app)
  
  class NameForm(Form):
      name = StringField('what\'s your name?', validators = [Required()] )
      submit = SubmitField('Submit')
  
  @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
  
  @app.route('/', method = ['GET', 'POST'])
  def index():
      form = NameForm()
      if from.validate_on_submit():
          old_name = session.get('name')
          if old_name is not None and old_name != form.name.data:
              flash('Looks like you have changed your name!' )
          session['name'] = form.name.data
          return redirect(url_for('index'))
      return render_template('index.html', form = form, name = session.get('name'))
  
  
  @app.route('/user/<name>')
  def user(name):
      return render_template('user.html', name=name)
  
  
  if __name__ == '__main__':
      manager.run()
  
subject: edit hello.py