ddt运行测试方法时报错AttributeError: type object 'TestHttpRq' has no attribute 'test_http_rq_login'

import unittest
import ddt  #装饰器
from ddt import ddt,data,unpack #导入ddt中的各个模块
from homework.unittest_http_request_20190321.Method_http_request import *

@ddt  #装饰测试类
class TestHttpRq(unittest.TestCase): #测试类-get请求

    @data({"mobilephone":"","pwd":"183456"},
          {"mobilephone":"18688773467","pwd":""},
          {"mobilephone": "18688773467", "pwd": "123457"},
          {"mobilephone":"18688773467","pwd":"123456"}) #装饰方法，遍历data中的元素
    def test_http_rq_login(self,login_data):#测试用例必须以test开头，不然报错
      exp = ["用户名或密码错误","登录成功","手机号不能为空","密码不能为空"]
      res = HttpRequest("get",login_data).http_request().json()['msg']
      self.assertIn(res,exp)#断言,判断实际值与预期值是否一致

D:Python34python.exe "D:Program FilesJetBrainsPyCharm Community Edition 2017.2.3helperspycharm\_jb_unittest_runner.py" --target unittest_http_rq.TestHttpRq.test_http_rq_login
Testing started at 13:10 ...
Launching unittests with arguments python -m unittest unittest_http_rq.TestHttpRq.test_http_rq_login in D:python15期homeworkddt_20190323

Traceback (most recent call last):
  File "D:Program FilesJetBrainsPyCharm Community Edition 2017.2.3helperspycharm\_jb_unittest_runner.py", line 35, in <module>
    main(argv=args, module=None, testRunner=unittestpy.TeamcityTestRunner, buffer=not JB_DISABLE_BUFFERING)
  File "D:Python34libunittestmain.py", line 92, in __init__
    self.parseArgs(argv)
  File "D:Python34libunittestmain.py", line 139, in parseArgs
    self.createTests()
  File "D:Python34libunittestmain.py", line 146, in createTests
    self.module)
  File "D:Python34libunittestloader.py", line 157, in loadTestsFromNames
    suites = [self.loadTestsFromName(name, module) for name in names]
  File "D:Python34libunittestloader.py", line 157, in <listcomp>
    suites = [self.loadTestsFromName(name, module) for name in names]
  File "D:Python34libunittestloader.py", line 125, in loadTestsFromName
    parent, obj = obj, getattr(obj, part)
AttributeError: type object 'TestHttpRq' has no attribute 'test_http_rq_login'

Process finished with exit code 1
Empty test suite.

_{运行程序时将鼠标定位在类或者程序外运行解决，ddt只能运行整体，不能运行局部即单个测试方法}