django - 导入错误: No module named 'models' in Python 3

Question

我有一个新的 Python 项目，其中的 models.py 文件如下所示:

from django.db import models
from django.contrib.auth.models import User
from django.core.validators import MinValueValidator, MaxValueValidator

class Metric(models.Model):
  users = models.ManyToManyField(User, through = 'Vote')
  name = models.CharField(max_length = 255)

class Vote(models.Model):
  metric = models.ForeignKey(Metric, on_delete = models.CASCADE)
  user = models.ForeignKey(User, on_delete = models.CASCADE)
  rating = models.IntegerField(validators = [MinValueValidator(0), MaxValueValidator(10)])
  email = models.EmailField

  def __str__(self):
    return str(self.rating)

和一个像这样的 admin.py 文件:

from django.contrib import admin
from models import Metric, Vote

admin.site.register(Metric)
admin.site.register(Vote)

使用 Python 2.7.5 运行此程序时，启动应用程序工作正常。当我尝试使用 Python 3.5.1 运行它时，出现错误 ImportError: No module named 'models'，并带有以下回溯:

Unhandled exception in thread started by <function check_errors.<locals>.wrapper at 0x103bd2b70>
Traceback (most recent call last):
  File "/Users/sashacooper/pyenv/lib/python3.5/site-packages/django/utils/autoreload.py", line 226, in wrapper
    fn(*args, **kwargs)
  File "/Users/sashacooper/pyenv/lib/python3.5/site-packages/django/core/management/commands/runserver.py", line 113, in inner_run
    autoreload.raise_last_exception()
  File "/Users/sashacooper/pyenv/lib/python3.5/site-packages/django/utils/autoreload.py", line 249, in raise_last_exception
    six.reraise(*_exception)
  File "/Users/sashacooper/pyenv/lib/python3.5/site-packages/django/utils/six.py", line 685, in reraise
    raise value.with_traceback(tb)
  File "/Users/sashacooper/pyenv/lib/python3.5/site-packages/django/utils/autoreload.py", line 226, in wrapper
    fn(*args, **kwargs)
  File "/Users/sashacooper/pyenv/lib/python3.5/site-packages/django/__init__.py", line 27, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/Users/sashacooper/pyenv/lib/python3.5/site-packages/django/apps/registry.py", line 115, in populate
    app_config.ready()
  File "/Users/sashacooper/pyenv/lib/python3.5/site-packages/django/contrib/admin/apps.py", line 23, in ready
    self.module.autodiscover()
  File "/Users/sashacooper/pyenv/lib/python3.5/site-packages/django/contrib/admin/__init__.py", line 26, in autodiscover
    autodiscover_modules('admin', register_to=site)
  File "/Users/sashacooper/pyenv/lib/python3.5/site-packages/django/utils/module_loading.py", line 50, in autodiscover_modules
    import_module('%s.%s' % (app_config.name, module_to_search))
  File "/Users/sashacooper/pyenv/lib/python3.5/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 986, in _gcd_import
  File "<frozen importlib._bootstrap>", line 969, in _find_and_load
  File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 662, in exec_module
  File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
  File "/Users/sashacooper/Desktop/pogroms/crockerometer2/crockerometer/admin.py", line 2, in <module>
    from models import Metric, Vote

我尝试将 from __future__ importabsolute_import 添加到每个类似标题的 Stack Overflow 帖子的 admin.py 文件的开头，但它没有改变错误。是什么原因造成的？

Answer 1

在 Python 3 中，当您使用相对导入时，您必须告诉它:

from .models import ...