title: 404 Not found error while using flask
body: <p>I'm learning web development in python with the flask. The code doesn't show any error, but when I run it, the browser shows Error - 404 Not Found.
  Code:</p>
  
  <pre><code>from flask import Flask, redirect, url_for
  app = Flask(__name__)
  @app.route('/admin/')
  def hello_admin():
     return 'Hello Admin'
  @app.route('/guest/&lt;guest&gt;')
  def hello_guest(guest):
     return 'Hello %s as Guest' % guest
  @app.route('/user/&lt;name&gt;')
  def hello_user(name):
     if name =='admin':
        return redirect(url_for('hello_admin'))
     else:
        return redirect(url_for('hello_guest',guest = name))
  if __name__ == '__main__':
     app.run(debug=True)
  </code></pre>
  
  <p>Output in Chrome:
  Not Found
  The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again</p>