错误信息是：No module named postgresql.base。

我正在尝试将一个Django应用迁移到PostgreSQL，但是我遇到了一个问题，即Django无法识别已经安装的PostgreSQL。我已经在我的机器上安装了它，并且在我的计算机上运行得很好，但是当我尝试在settings.py中将其设置为默认数据库时，我收到错误消息：

错误为：没有名为postgresql.base的模块

我按照这里的两个教程（链接）和（链接）尝试了安装PostgreSQL与Django的步骤，但是我仍然遇到这个错误。我应该在我的虚拟环境中安装PostgreSQL吗？我尝试过这样做，但是没有成功。

settings.py

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'pygamers',
        'USER': 'myusername',
        'PASSWORD': '',
        'HOST': 'localhost',
        'PORT': '5432',
    }
}

完整的追踪信息如下：

Unhandled exception in thread started by 
Traceback (most recent call last):
  File "/Users/tomeldridge/Desktop/Misc/Hobbies/Programming/Projects/Pygamers/venv/lib/python2.7/site-packages/django/utils/autoreload.py", line 226, in wrapper
    fn(*args, **kwargs)
  File "/Users/tomeldridge/Desktop/Misc/Hobbies/Programming/Projects/Pygamers/venv/lib/python2.7/site-packages/django/core/management/commands/runserver.py", line 109, in inner_run
    autoreload.raise_last_exception()
  File "/Users/tomeldridge/Desktop/Misc/Hobbies/Programming/Projects/Pygamers/venv/lib/python2.7/site-packages/django/utils/autoreload.py", line 249, in raise_last_exception
    six.reraise(*_exception)
  File "/Users/tomeldridge/Desktop/Misc/Hobbies/Programming/Projects/Pygamers/venv/lib/python2.7/site-packages/django/utils/autoreload.py", line 226, in wrapper
    fn(*args, **kwargs)
  File "/Users/tomeldridge/Desktop/Misc/Hobbies/Programming/Projects/Pygamers/venv/lib/python2.7/site-packages/django/__init__.py", line 18, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/Users/tomeldridge/Desktop/Misc/Hobbies/Programming/Projects/Pygamers/venv/lib/python2.7/site-packages/django/apps/registry.py", line 108, in populate
    app_config.import_models(all_models)
  File "/Users/tomeldridge/Desktop/Misc/Hobbies/Programming/Projects/Pygamers/venv/lib/python2.7/site-packages/django/apps/config.py", line 202, in import_models
    self.models_module = import_module(models_module_name)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
  File "/Users/tomeldridge/Desktop/Misc/Hobbies/Programming/Projects/Pygamers/userprofile/models.py", line 2, in 
    from django.contrib.auth.models import User
  File "/Users/tomeldridge/Desktop/Misc/Hobbies/Programming/Projects/Pygamers/venv/lib/python2.7/site-packages/django/contrib/auth/models.py", line 4, in 
    from django.contrib.auth.base_user import AbstractBaseUser, BaseUserManager
  File "/Users/tomeldridge/Desktop/Misc/Hobbies/Programming/Projects/Pygamers/venv/lib/python2.7/site-packages/django/contrib/auth/base_user.py", line 49, in 
    class AbstractBaseUser(models.Model):
  File "/Users/tomeldridge/Desktop/Misc/Hobbies/Programming/Projects/Pygamers/venv/lib/python2.7/site-packages/django/db/models/base.py", line 108, in __new__
    new_class.add_to_class('_meta', Options(meta, app_label))
  File "/Users/tomeldridge/Desktop/Misc/Hobbies/Programming/Projects/Pygamers/venv/lib/python2.7/site-packages/django/db/models/base.py", line 299, in add_to_class
    value.contribute_to_class(cls, name)
  File "/Users/tomeldridge/Desktop/Misc/Hobbies/Programming/Projects/Pygamers/venv/lib/python2.7/site-packages/django/db/models/options.py", line 263, in contribute_to_class
    self.db_table = truncate_name(self.db_table, connection.ops.max_name_length())
  File "/Users/tomeldridge/Desktop/Misc/Hobbies/Programming/Projects/Pygamers/venv/lib/python2.7/site-packages/django/db/__init__.py", line 36, in __getattr__
    return getattr(connections[DEFAULT_DB_ALIAS], item)
  File "/Users/tomeldridge/Desktop/Misc/Hobbies/Programming/Projects/Pygamers/venv/lib/python2.7/site-packages/django/db/utils.py", line 212, in __getitem__
    backend = load_backend(db['ENGINE'])
  File "/Users/tomeldridge/Desktop/Misc/Hobbies/Programming/Projects/Pygamers/venv/lib/python2.7/site-packages/django/db/utils.py", line 135, in load_backend
    raise ImproperlyConfigured(error_msg)
django.core.exceptions.ImproperlyConfigured: 'django.db.backends.postgresql'不是可用的数据库后端。
请尝试使用'django.db.backends.XXX'，其中XXX是以下之一：
    'mysql'，'oracle'，'sqlite3'
错误为：没有名为postgresql.base的模块