odoo自定义模块安装导入错误：没有名为examinations的模块

Question

我在Odoo9上创建了一个超级简单的定制模块。但我无法安装，我得到一个错误：

Traceback (most recent call last):
  File "/opt/odoo/openerp/modules/loading.py", line 123, in load_module_graph
    load_openerp_module(package.name)
  File "/opt/odoo/openerp/modules/module.py", line 324, in load_openerp_module
    __import__('openerp.addons.' + module_name)
  File "/opt/odoo/openerp/modules/module.py", line 60, in load_module
    f, path, descr = imp.find_module(module_part, ad_paths)
ImportError: No module named examinations

文件：

初始py：

^{pr2}$

我的清单

# -*- coding: utf-8 -*-
{
    'name': "examinations",

    'summary': """
        Short (1 phrase/line) summary of the module's purpose, used as
        subtitle on modules listing or apps.openerp.com""",

    'description': """
    Examinations Management Module
    """,

    'author': "My Company",
    'website': "http://www.yourcompany.com",

    'category': 'Education and Support',
    'version': '0.1',

    'depends': ['base'],

    'data': [
        'views/examinations_view.xml',
    ],

    'installable': True,
}

我的模块examinations.py在models目录中。代码是：

# -*- coding: utf-8 -*-

from openerp import models, fields, api

class Examinations(models.Model):
    _name = 'examinations.custom'

    name = fields.Char('Examination',required=True)
    subject = fields.Integer('Subject', required=True)
    exam_date = fields.Datetime('Date and Time of Date')
    exam_hall = fields.Char('Examination Hall')
    max_marks = fields.Integer('Maximum Marks')

我不明白怎么回事。我创造了初始py文件、清单、模型、视图。在