我正在尝试按照烧瓶教程的说明构建一个URL

但是我继续得到这个NameError

name ‘url_for’ is not defined

这是代码：

from flask import Flask

app = Flask(__name__)

@app.route('/')

def Index() : pass

@app.route ('/ login')

def loGin() : pass

@app.route('/user/')

def profile( username) : pass

with app.test_request_context() :

print url_for('Index')

print url_for('loGin')

print url_for('loGin', next='/')

print url_for('profile', username = 'Jon DD')

这是总错误消息：

eloiim:minimalapp iivri.andre$export FLASK_APP=Greet.py

eloiim:minimalapp iivri.andre$flask run

Traceback (most recent call last):

File "/usr/local/bin/flask", line 11, in

sys.exit(main())

File "/usr/local/lib/python2.7/site-packages/flask/cli.py", line 478, in main

cli.main(args=args, prog_name=name)

File "/usr/local/lib/python2.7/site-packages/flask/cli.py", line 345, in main

return AppGroup.main(self, *args, **kwargs)

File "/usr/local/lib/python2.7/site-packages/click/core.py", line 696, in main

rv = self.invoke(ctx)

File "/usr/local/lib/python2.7/site-packages/click/core.py", line 1060, in invoke

return _process_result(sub_ctx.command.invoke(sub_ctx))

File "/usr/local/lib/python2.7/site-packages/click/core.py", line 889, in invoke

return ctx.invoke(self.callback, **ctx.params)

File "/usr/local/lib/python2.7/site-packages/click/core.py", line 534, in invoke

return callback(*args, **kwargs)

File "/usr/local/lib/python2.7/site-packages/click/decorators.py", line 64, in new_func

return ctx.invoke(f, obj, *args[1:], **kwargs)

File "/usr/local/lib/python2.7/site-packages/click/core.py", line 534, in invoke

return callback(*args, **kwargs)

File "/usr/local/lib/python2.7/site-packages/flask/cli.py", line 388, in run_command

app = DispatchingApp(info.load_app, use_eager_loading=eager_loading)

File "/usr/local/lib/python2.7/site-packages/flask/cli.py", line 124, in __init__

self._load_unlocked()

File "/usr/local/lib/python2.7/site-packages/flask/cli.py", line 148, in _load_unlocked

self._app = rv = self.loader()

File "/usr/local/lib/python2.7/site-packages/flask/cli.py", line 209, in load_app

rv = locate_app(self.app_import_path)

File "/usr/local/lib/python2.7/site-packages/flask/cli.py", line 89, in locate_app

__import__(module)

File "/Users/iivri.andre/Documents/minimalapp/Greet.py", line 16, in

print url_for('Index')

NameError: name 'url_for' is not defined

我不确定是什么问题.非常感谢帮助.

干杯

安德烈.