名稱「_」沒有定義

Question

我收到以下錯誤，當我執行：

$ python manage.py schemamigration myapp --initial 

似乎抱怨這一行：

audio_file = models.FileField(_("Audio file"), upload_to=get_audio_upload_path) 

我不知道我是什麼做錯了。請幫忙。

Traceback (most recent call last): 
File "/Users/home/Desktop/Web Development/Aptana Studio 3.0/musicproject/src/manage.py", line 10, in <module> 
execute_from_command_line(sys.argv) 
File "/Users/home/virtualenv/venv/lib/python2.7/site-packages/django/core/management/__init__.py", line 443, in execute_from_command_line 
utility.execute() 
File "/Users/home/virtualenv/venv/lib/python2.7/site-packages/django/core/management/__init__.py", line 382, in execute 
self.fetch_command(subcommand).run_from_argv(self.argv) 
File "/Users/home/virtualenv/venv/lib/python2.7/site-packages/django/core/management/base.py", line 196, in run_from_argv 
self.execute(*args, **options.__dict__) 
File "/Users/home/virtualenv/venv/lib/python2.7/site-packages/django/core/management/base.py", line 231, in execute 
self.validate() 
File "/Users/home/virtualenv/venv/lib/python2.7/site-packages/django/core/management/base.py", line 266, in validate 
num_errors = get_validation_errors(s, app) 
File "/Users/home/virtualenv/venv/lib/python2.7/site-packages/django/core/management/validation.py", line 30, in get_validation_errors 
for (app_name, error) in get_app_errors().items(): 
File "/Users/home/virtualenv/venv/lib/python2.7/site-packages/django/db/models/loading.py", line 158, in get_app_errors 
self._populate() 
File "/Users/home/virtualenv/venv/lib/python2.7/site-packages/django/db/models/loading.py", line 64, in _populate 
self.load_app(app_name, True) 
File "/Users/home/virtualenv/venv/lib/python2.7/site-packages/django/db/models/loading.py", line 88, in load_app 
models = import_module('.models', app_name) 
File "/Users/home/virtualenv/venv/lib/python2.7/site-packages/django/utils/importlib.py", line 35, in import_module 
__import__(name) 
File "/Users/home/Desktop/Web Development/Aptana Studio 3.0/musicproject/src/myapp/models.py", line 39, in <module> 
class AudioTrack(models.Model): 
File "/Users/home/Desktop/Web Development/Aptana Studio 3.0/musicproject/src/myapp/models.py", line 51, in AudioTrack 
audio_file = models.FileField(_("Audio file"), upload_to=get_audio_upload_path) 
NameError: name '_' is not defined 

這是我的model.py文件：

import os 
import mimetypes 

from django.conf import settings 
from django.contrib.auth.models import User 

from django.db import models 

GENRE_CHOICES = (
      ('R', 'Rock'), 
      ('J/B', 'Jazz/Blues'), 
      ('B', 'Blues'), 
      ('R&B' 'R&B'), 
      ('J', 'Jazz'), 
      ('P', 'Pop'), 
      ('H', 'Hip-Hop'),  
      ) 


def get_upload_path(dirname, obj, filename): 
    return os.path.join("audiotracks", dirname, obj.user.username, filename) 

def get_audio_upload_path(obj, filename): 
    return get_upload_path("audio_files", obj, filename) 

class Genre(models.Model): 
    genre_choices = models.CharField(max_length=1, choices=GENRE_CHOICES) 
    slug = models.SlugField(max_length = 40, unique = True) #so as to have a dedicated page for each category 
    description = models.TextField() 

def __unicode__(self): 
     return self.title 

def get_absolute_url(self): 
    return "/genres/%s/" % self.slug 

class AudioTrack(models.Model): 
    class Meta: 
     abstract = True 

    user = models.ForeignKey(User, 
     related_name = "tracks", 
     blank = True, 
     null = True 
) 

added_on = models.DateTimeField(auto_now_add=True, null = True) 
updated_on = models.DateTimeField(auto_now=True, null = True) 
audio_file = models.FileField(_("Audio file"), upload_to=get_audio_upload_path) 
title = models.CharField(_("Title"), max_length="200", null=True) 
description = models.TextField(_("Description"), null=True, blank=True) 
slug = models.SlugField(max_length = 40, unique = True) #so as to have a dedicated page for each category 
genres = models.ManyToManyField(Genre) 

def __unicode__(self): 
    return "Track '%s' uploaded by '%s'" % (self.title, self.user.username) 

@property 
def mimetype(self): 
    if not hasattr(self, '_mimetype'): 
     self._mimetype = mimetypes.guess_type(self.audio_file.path)[0] 
    return self._mimetype 

@property 
def filetype(self): 
    if '/' in self.mimetype: 
     type_names = {'mpeg': 'MP3', 'ogg': 'Ogg Vorbis', 'wave':'wav', 'FLAC':'FLA'} 
     filetype = self.mimetype.split('/')[1] 
     return type_names.get(filetype, filetype) 
    else: 
     return self.mimetype 

@models.permalink 
def get_absolute_url(self): 
    # ('tracks.views.track_detail', [self.user.username, self.slug]) 
    return "/%s/%s/" %(self.genre, self.slug) 

if hasattr(settings, 'AUDIOTRACKS_MODEL'): 
    app_name, model_name = settings.AUDIOTRACKS_MODEL.split('.') 
    Track = models.get_model(app_name, model_name) 
else: 
    class Track(AudioTrack): 
     pass 

class Genre_Track(models.Model): #links genre to tracks 
    audio_track = models.ForeignKey(AudioTrack) 
    genre = models.ForeignKey(Genre) 

Answer 1

您錯過這個：

from django.utils.translation import gettext as _ 

從Django i18n docs閱讀更多相關資訊。這是Django/python項目中的慣用方法。