前往小程序,Get更优阅读体验!
立即前往
首页
学习
活动
专区
工具
TVP
发布
社区首页 >专栏 >Selenium2+python自动化56-unittest之断言(assert)

Selenium2+python自动化56-unittest之断言(assert)

作者头像
上海-悠悠
发布2018-04-08 16:14:37
6650
发布2018-04-08 16:14:37
举报

前言

在测试用例中,执行完测试用例后,最后一步是判断测试结果是pass还是fail,自动化测试脚本里面一般把这种生成测试结果的方法称为断言(assert)。

用unittest组件测试用例的时候,断言的方法还是很多的,下面介绍几种常用的断言方法:assertEqual、assertIn、assertTrue。

一、简单案例

1.下面写了4个case,其中第四个是执行失败的

代码语言:javascript
复制
# coding:utf-8
import unittest
class Test(unittest.TestCase):
    def test01(self):
        '''判断 a == b '''
        a = 1
        b = 1
        self.assertEqual(a, b)

    def test02(self):
        '''判断 a in b '''
        a = "hello"
        b = "hello world!"
        self.assertIn(a, b)

    def test03(self):
        '''判断 a is True '''
        a = True
        self.assertTrue(a)

    def test04(self):
        '''失败案例'''
        a = "上海-悠悠"
        b = "yoyo"
        self.assertEqual(a, b)

if __name__ == "__main__":
    unittest.main()

2.执行结果如下

代码语言:javascript
复制
Failure
Expected :'\xe4\xb8\x8a\xe6\xb5\xb7-\xe6\x82\xa0\xe6\x82\xa0'
Actual   :'yoyo'
 <Click to see difference>

Traceback (most recent call last):
  File "D:\test\yoyotest\kecheng\test12.py", line 27, in test04
    self.assertEqual(a, b)
AssertionError: '\xe4\xb8\x8a\xe6\xb5\xb7-\xe6\x82\xa0\xe6\x82\xa0' != 'yoyo'

3.执行的结果,中文编码不对,没正常显示中文,遇到这种情况,可以自定义异常输出

二、自定义异常输出

1.以assertEqual为例分析:

assertEqual(self, first, second, msg=None) Fail if the two objects are unequal as determined by the '==' operator.

翻译:如果两个对象不能相等,就返回失败,相当于return: first==second

2.这里除了相比较的两个参数first和second,还有第三个参数msg=None,这个msg参数就是遇到异常后自定义输出信息

三、unittest常用的断言方法

1.assertEqual(self, first, second, msg=None)

--判断两个参数相等:first == second

2.assertNotEqual(self, first, second, msg=None)

--判断两个参数不相等:first != second

3.assertIn(self, member, container, msg=None)

--判断是字符串是否包含:member in container

4.assertNotIn(self, member, container, msg=None)

--判断是字符串是否不包含:member not in container

5.assertTrue(self, expr, msg=None)

--判断是否为真:expr is True

6.assertFalse(self, expr, msg=None)

--判断是否为假:expr is False

7.assertIsNone(self, obj, msg=None)

--判断是否为None:obj is None

8.assertIsNotNone(self, obj, msg=None) --判断是否不为None:obj is not None

四、unittest所有断言方法

1.下面是unittest框架支持的所有断言方法,有兴趣的同学可以慢慢看。

代码语言:javascript
复制
|  assertAlmostEqual(self, first, second, places=None, msg=None, delta=None)
|      Fail if the two objects are unequal as determined by their
|      difference rounded to the given number of decimal places
|      (default 7) and comparing to zero, or by comparing that the
|      between the two objects is more than the given delta.
|      
|      Note that decimal places (from zero) are usually not the same
|      as significant digits (measured from the most signficant digit).
|      
|      If the two objects compare equal then they will automatically
|      compare almost equal.
|  
|  assertAlmostEquals = assertAlmostEqual(self, first, second, places=None, msg=None, delta=None)
|  
|  assertDictContainsSubset(self, expected, actual, msg=None)
|      Checks whether actual is a superset of expected.
|  
|  assertDictEqual(self, d1, d2, msg=None)
|  
|  assertEqual(self, first, second, msg=None)
|      Fail if the two objects are unequal as determined by the '=='
|      operator.
|  
|  assertEquals = assertEqual(self, first, second, msg=None)
|  
|  assertFalse(self, expr, msg=None)
|      Check that the expression is false.
|  
|  assertGreater(self, a, b, msg=None)
|      Just like self.assertTrue(a > b), but with a nicer default message.
|  
|  assertGreaterEqual(self, a, b, msg=None)
|      Just like self.assertTrue(a >= b), but with a nicer default message.
|  
|  assertIn(self, member, container, msg=None)
|      Just like self.assertTrue(a in b), but with a nicer default message.
|  
|  assertIs(self, expr1, expr2, msg=None)
|      Just like self.assertTrue(a is b), but with a nicer default message.
|  
|  assertIsInstance(self, obj, cls, msg=None)
|      Same as self.assertTrue(isinstance(obj, cls)), with a nicer
|      default message.
|  
|  assertIsNone(self, obj, msg=None)
|      Same as self.assertTrue(obj is None), with a nicer default message.
|  
|  assertIsNot(self, expr1, expr2, msg=None)
|      Just like self.assertTrue(a is not b), but with a nicer default message.
|  
|  assertIsNotNone(self, obj, msg=None)
|      Included for symmetry with assertIsNone.
|  
|  assertItemsEqual(self, expected_seq, actual_seq, msg=None)
|      An unordered sequence specific comparison. It asserts that
|      actual_seq and expected_seq have the same element counts.
|      Equivalent to::
|      
|          self.assertEqual(Counter(iter(actual_seq)),
|                           Counter(iter(expected_seq)))
|      
|      Asserts that each element has the same count in both sequences.
|      Example:
|          - [0, 1, 1] and [1, 0, 1] compare equal.
|          - [0, 0, 1] and [0, 1] compare unequal.
|  
|  assertLess(self, a, b, msg=None)
|      Just like self.assertTrue(a < b), but with a nicer default message.
|  
|  assertLessEqual(self, a, b, msg=None)
|      Just like self.assertTrue(a <= b), but with a nicer default message.
|  
|  assertListEqual(self, list1, list2, msg=None)
|      A list-specific equality assertion.
|      
|      Args:
|          list1: The first list to compare.
|          list2: The second list to compare.
|          msg: Optional message to use on failure instead of a list of
|                  differences.
|  
|  assertMultiLineEqual(self, first, second, msg=None)
|      Assert that two multi-line strings are equal.
|  
|  assertNotAlmostEqual(self, first, second, places=None, msg=None, delta=None)
|      Fail if the two objects are equal as determined by their
|      difference rounded to the given number of decimal places
|      (default 7) and comparing to zero, or by comparing that the
|      between the two objects is less than the given delta.
|      
|      Note that decimal places (from zero) are usually not the same
|      as significant digits (measured from the most signficant digit).
|      
|      Objects that are equal automatically fail.
|  
|  assertNotAlmostEquals = assertNotAlmostEqual(self, first, second, places=None, msg=None, delta=None)
|  
|  assertNotEqual(self, first, second, msg=None)
|      Fail if the two objects are equal as determined by the '!='
|      operator.
|  
|  assertNotEquals = assertNotEqual(self, first, second, msg=None)
|  
|  assertNotIn(self, member, container, msg=None)
|      Just like self.assertTrue(a not in b), but with a nicer default message.
|  
|  assertNotIsInstance(self, obj, cls, msg=None)
|      Included for symmetry with assertIsInstance.
|  
|  assertNotRegexpMatches(self, text, unexpected_regexp, msg=None)
|      Fail the test if the text matches the regular expression.
|  
|  assertRaises(self, excClass, callableObj=None, *args, **kwargs)
|      Fail unless an exception of class excClass is raised
|      by callableObj when invoked with arguments args and keyword
|      arguments kwargs. If a different type of exception is
|      raised, it will not be caught, and the test case will be
|      deemed to have suffered an error, exactly as for an
|      unexpected exception.
|      
|      If called with callableObj omitted or None, will return a
|      context object used like this::
|      
|           with self.assertRaises(SomeException):
|               do_something()
|      
|      The context manager keeps a reference to the exception as
|      the 'exception' attribute. This allows you to inspect the
|      exception after the assertion::
|      
|          with self.assertRaises(SomeException) as cm:
|              do_something()
|          the_exception = cm.exception
|          self.assertEqual(the_exception.error_code, 3)
|  
|  assertRaisesRegexp(self, expected_exception, expected_regexp, callable_obj=None, *args, **kwargs)
|      Asserts that the message in a raised exception matches a regexp.
|      
|      Args:
|          expected_exception: Exception class expected to be raised.
|          expected_regexp: Regexp (re pattern object or string) expected
|                  to be found in error message.
|          callable_obj: Function to be called.
|          args: Extra args.
|          kwargs: Extra kwargs.
|  
|  assertRegexpMatches(self, text, expected_regexp, msg=None)
|      Fail the test unless the text matches the regular expression.
|  
|  assertSequenceEqual(self, seq1, seq2, msg=None, seq_type=None)
|      An equality assertion for ordered sequences (like lists and tuples).
|      
|      For the purposes of this function, a valid ordered sequence type is one
|      which can be indexed, has a length, and has an equality operator.
|      
|      Args:
|          seq1: The first sequence to compare.
|          seq2: The second sequence to compare.
|          seq_type: The expected datatype of the sequences, or None if no
|                  datatype should be enforced.
|          msg: Optional message to use on failure instead of a list of
|                  differences.
|  
|  assertSetEqual(self, set1, set2, msg=None)
|      A set-specific equality assertion.
|      
|      Args:
|          set1: The first set to compare.
|          set2: The second set to compare.
|          msg: Optional message to use on failure instead of a list of
|                  differences.
|      
|      assertSetEqual uses ducktyping to support different types of sets, and
|      is optimized for sets specifically (parameters must support a
|      difference method).
|  
|  assertTrue(self, expr, msg=None)
|      Check that the expression is true.
|  
|  assertTupleEqual(self, tuple1, tuple2, msg=None)
|      A tuple-specific equality assertion.
|      
|      Args:
|          tuple1: The first tuple to compare.
|          tuple2: The second tuple to compare.
|          msg: Optional message to use on failure instead of a list of
|                  differences.
本文参与 腾讯云自媒体分享计划,分享自微信公众号。
原始发表:2017-04-10,如有侵权请联系 cloudcommunity@tencent.com 删除

本文分享自 从零开始学自动化测试 微信公众号,前往查看

如有侵权,请联系 cloudcommunity@tencent.com 删除。

本文参与 腾讯云自媒体分享计划  ,欢迎热爱写作的你一起参与!

评论
登录后参与评论
0 条评论
热度
最新
推荐阅读
领券
问题归档专栏文章快讯文章归档关键词归档开发者手册归档开发者手册 Section 归档