Pythonunittest单元测试框架

测试用例¶

class unittest.TestCase(methodName='runTest')¶

Instances of the TestCase class represent the logical test units

in the unittest universe. This class is intended to be used as a base

class, with specific tests being implemented by concrete subclasses. This class

implements the interface needed by the test runner to allow it to drive the

tests, and methods that the test code can use to check for and report various

kinds of failure.

Each instance of TestCase will run a single base method: the method

named methodName.

In most uses of TestCase, you will neither change

the methodName nor reimplement the default runTest() method.

在 3.2 版更改: TestCase can be instantiated successfully without providing a

methodName. This makes it easier to experiment with TestCase

from the interactive interpreter.

TestCase instances provide three groups of methods: one group used

to run the test, another used by the test implementation to check conditions

and report failures, and some inquiry methods allowing information about the

test itself to be gathered.

第一组（用于运行测试的）方法是：

setUp()¶

Method called to prepare the test fixture. This is called immediately

before calling the test method; other than AssertionError or SkipTest,

any exception raised by this method will be considered an error rather than

a test failure. The default implementation does nothing.

tearDown()¶

Method called immediately after the test method has been called and the

result recorded. This is called even if the test method raised an

exception, so the implementation in subclasses may need to be particularly

careful about checking internal state. Any exception, other than

AssertionError or SkipTest, raised by this method will be

considered an additional error rather than a test failure (thus increasing

the total number of reported errors). This method will only be called if

the setUp() succeeds, regardless of the outcome of the test method.

The default implementation does nothing.

setUpClass()¶

A class method called before tests in an individual class are run.

setUpClass is called with the class as the only argument

and must be decorated as a classmethod():

@classmethod
defsetUpClass(cls):
...

查看 Class and Module Fixtures 获取更详细的说明。

3.2 新版功能.

tearDownClass()¶

A class method called after tests in an individual class have run.

tearDownClass is called with the class as the only argument

and must be decorated as a classmethod():

@classmethod
deftearDownClass(cls):
...

查看 Class and Module Fixtures 获取更详细的说明。

3.2 新版功能.

run(result=None)¶

Run the test, collecting the result into the TestResult object

passed as result. If result is omitted or None, a temporary

result object is created (by calling the defaultTestResult()

method) and used. The result object is returned to run()'s

caller.

The same effect may be had by simply calling the TestCase

instance.

在 3.3 版更改: Previous versions of run did not return the result. Neither did

calling an instance.

skipTest(reason)¶

Calling this during a test method or setUp() skips the current

test. See 跳过测试与预计的失败 for more information.

3.1 新版功能.

subTest(msg=None, **params)¶

Return a context manager which executes the enclosed code block as a

subtest. msg and params are optional, arbitrary values which are

displayed whenever a subtest fails, allowing you to identify them

clearly.

A test case can contain any number of subtest declarations, and

they can be arbitrarily nested.

查看 Distinguishing test iterations using subtests 获取更详细的信息。

3.4 新版功能.

debug()¶

Run the test without collecting the result. This allows exceptions raised

by the test to be propagated to the caller, and can be used to support

running tests under a debugger.

The TestCase class provides several assert methods to check for and

report failures. The following table lists the most commonly used methods

(see the tables below for more assert methods):

Method	Checks that	New in
assertEqual(a,b)	a==b
assertNotEqual(a,b)	a!=b
assertTrue(x)	bool(x)isTrue
assertFalse(x)	bool(x)isFalse
assertIs(a,b)	aisb	3.1
assertIsNot(a,b)	aisnotb	3.1
assertIsNone(x)	xisNone	3.1
assertIsNotNone(x)	xisnotNone	3.1
assertIn(a,b)	ainb	3.1
assertNotIn(a,b)	anotinb	3.1
assertIsInstance(a,b)	isinstance(a,b)	3.2
assertNotIsInstance(a,b)	notisinstance(a,b)	3.2

All the assert methods accept a msg argument that, if specified, is used

as the error message on failure (see also longMessage).

Note that the msg keyword argument can be passed to assertRaises(),

assertRaisesRegex(), assertWarns(), assertWarnsRegex()

only when they are used as a context manager.

assertEqual(first, second, msg=None)¶

Test that first and second are equal. If the values do not

compare equal, the test will fail.

In addition, if first and second are the exact same type and one of

list, tuple, dict, set, frozenset or str or any type that a subclass

registers with addTypeEqualityFunc() the type-specific equality

function will be called in order to generate a more useful default

error message (see also the list of type-specific methods).

在 3.1 版更改: Added the automatic calling of type-specific equality function.

在 3.2 版更改: assertMultiLineEqual() added as the default type equality

function for comparing strings.

assertNotEqual(first, second, msg=None)¶

Test that first and second are not equal. If the values do

compare equal, the test will fail.

assertTrue(expr, msg=None)¶

assertFalse(expr, msg=None)¶

Test that expr is true (or false).

Note that this is equivalent to bool(expr)isTrue and not to expr

isTrue (use assertIs(expr,True) for the latter). This method

should also be avoided when more specific methods are available (e.g.

assertEqual(a,b) instead of assertTrue(a==b)), because they

provide a better error message in case of failure.

assertIs(first, second, msg=None)¶

assertIsNot(first, second, msg=None)¶

Test that first and second evaluate (or don't evaluate) to the

same object.

3.1 新版功能.

assertIsNone(expr, msg=None)¶

assertIsNotNone(expr, msg=None)¶

Test that expr is (or is not) None.

3.1 新版功能.

assertIn(member, container, msg=None)¶

assertNotIn(member, container, msg=None)¶

Test that member is (or is not) in container.

3.1 新版功能.

assertIsInstance(obj, cls, msg=None)¶

assertNotIsInstance(obj, cls, msg=None)¶

Test that obj is (or is not) an instance of cls (which can be a

class or a tuple of classes, as supported by isinstance()).

To check for the exact type, use assertIs(type(obj),cls).

3.2 新版功能.

It is also possible to check the production of exceptions, warnings, and

log messages using the following methods:

Method	Checks that	New in
assertRaises(exc,fun,*args,**kwds)	fun(*args,**kwds) raises exc
assertRaisesRegex(exc,r,fun,*args,**kwds)	fun(*args,**kwds) raises exc and the message matches regex r	3.1
assertWarns(warn,fun,*args,**kwds)	fun(*args,**kwds) raises warn	3.2
assertWarnsRegex(warn,r,fun,*args,**kwds)	fun(*args,**kwds) raises warn and the message matches regex r	3.2
assertLogs(logger,level)	The with block logs on logger with minimum level	3.4

assertRaises(exception, callable, *args, **kwds)¶

assertRaises(exception, *, msg=None)

Test that an exception is raised when callable is called with any

positional or keyword arguments that are also passed to

assertRaises(). The test passes if exception is raised, is an

error if another exception is raised, or fails if no exception is raised.

To catch any of a group of exceptions, a tuple containing the exception

classes may be passed as exception.

If only the exception and possibly the msg arguments are given,

return a context manager so that the code under test can be written

inline rather than as a function:

withself.assertRaises(SomeException):
do_something()

When used as a context manager, assertRaises() accepts the

additional keyword argument msg.

The context manager will store the caught exception object in its

exception attribute. This can be useful if the intention

is to perform additional checks on the exception raised:

withself.assertRaises(SomeException)ascm:
do_something()
the_exception=cm.exception
self.assertEqual(the_exception.error_code,3)

在 3.1 版更改: Added the ability to use assertRaises() as a context manager.

在 3.2 版更改: Added the exception attribute.

在 3.3 版更改: Added the msg keyword argument when used as a context manager.

assertRaisesRegex(exception, regex, callable, *args, **kwds)¶

assertRaisesRegex(exception, regex, *, msg=None)

Like assertRaises() but also tests that regex matches

on the string representation of the raised exception. regex may be

a regular expression object or a string containing a regular expression

suitable for use by re.search(). Examples:

self.assertRaisesRegex(ValueError,"invalid literal for.*XYZ'$",
int,'XYZ')

或者：

withself.assertRaisesRegex(ValueError,'literal'):
int('XYZ')

3.1 新版功能: 以方法名``assertRaisesRegexp``添加。

在 3.2 版更改: Renamed to assertRaisesRegex().

在 3.3 版更改: Added the msg keyword argument when used as a context manager.

assertWarns(warning, callable, *args, **kwds)¶

assertWarns(warning, *, msg=None)

Test that a warning is triggered when callable is called with any

positional or keyword arguments that are also passed to

assertWarns(). The test passes if warning is triggered and

fails if it isn't. Any exception is an error.

To catch any of a group of warnings, a tuple containing the warning

classes may be passed as warnings.

If only the warning and possibly the msg arguments are given,

return a context manager so that the code under test can be written

inline rather than as a function:

withself.assertWarns(SomeWarning):
do_something()

When used as a context manager, assertWarns() accepts the

additional keyword argument msg.

The context manager will store the caught warning object in its

warning attribute, and the source line which triggered the

warnings in the filename and lineno attributes.

This can be useful if the intention is to perform additional checks

on the warning caught:

withself.assertWarns(SomeWarning)ascm:
do_something()
self.assertIn('myfile.py',cm.filename)
self.assertEqual(320,cm.lineno)

This method works regardless of the warning filters in place when it

is called.

3.2 新版功能.

在 3.3 版更改: Added the msg keyword argument when used as a context manager.

assertWarnsRegex(warning, regex, callable, *args, **kwds)¶

assertWarnsRegex(warning, regex, *, msg=None)

Like assertWarns() but also tests that regex matches on the

message of the triggered warning. regex may be a regular expression

object or a string containing a regular expression suitable for use

by re.search(). Example:

self.assertWarnsRegex(DeprecationWarning,
r'legacy_function\(\) is deprecated',
legacy_function,'XYZ')

或者：

withself.assertWarnsRegex(RuntimeWarning,'unsafe frobnicating'):
frobnicate('/etc/passwd')

3.2 新版功能.

在 3.3 版更改: Added the msg keyword argument when used as a context manager.

assertLogs(logger=None, level=None)¶

A context manager to test that at least one message is logged on

the logger or one of its children, with at least the given

level.

If given, logger should be a logging.Logger object or a

str giving the name of a logger. The default is the root

logger, which will catch all messages.

If given, level should be either a numeric logging level or

its string equivalent (for example either "ERROR" or

logging.ERROR). The default is logging.INFO.

The test passes if at least one message emitted inside the with

block matches the logger and level conditions, otherwise it fails.

The object returned by the context manager is a recording helper

which keeps tracks of the matching log messages. It has two

attributes:

records¶

A list of logging.LogRecord objects of the matching

log messages.

output¶

A list of str objects with the formatted output of

matching messages.

示例:

withself.assertLogs('foo',level='INFO')ascm:
logging.getLogger('foo').info('first message')
logging.getLogger('foo.bar').error('second message')
self.assertEqual(cm.output,['INFO:foo:first message',
'ERROR:foo.bar:second message'])

3.4 新版功能.

There are also other methods used to perform more specific checks, such as:

Method	Checks that	New in
assertAlmostEqual(a,b)	round(a-b,7)==0
assertNotAlmostEqual(a,b)	round(a-b,7)!=0
assertGreater(a,b)	a>b	3.1
assertGreaterEqual(a,b)	a>=b	3.1
assertLess(a,b)	a<b	3.1
assertLessEqual(a,b)	a<=b	3.1
assertRegex(s,r)	r.search(s)	3.1
assertNotRegex(s,r)	notr.search(s)	3.2
assertCountEqual(a,b)	a and b have the same elements in the same number, regardless of their order.	3.2

assertAlmostEqual(first, second, places=7, msg=None, delta=None)¶

assertNotAlmostEqual(first, second, places=7, msg=None, delta=None)¶

Test that first and second are approximately (or not approximately)

equal by computing the difference, rounding to the given number of

decimal places (default 7), and comparing to zero. Note that these

methods round the values to the given number of decimal places (i.e.

like the round() function) and not significant digits.

If delta is supplied instead of places then the difference

between first and second must be less or equal to (or greater than) delta.

Supplying both delta and places raises a TypeError.

在 3.2 版更改: assertAlmostEqual() automatically considers almost equal objects

that compare equal. assertNotAlmostEqual() automatically fails

if the objects compare equal. Added the delta keyword argument.

assertGreater(first, second, msg=None)¶

assertGreaterEqual(first, second, msg=None)¶

assertLess(first, second, msg=None)¶

assertLessEqual(first, second, msg=None)¶

Test that first is respectively >, >=, < or <= than second depending

on the method name. If not, the test will fail:

>>> self.assertGreaterEqual(3,4)
AssertionError: "3" unexpectedly not greater than or equal to "4"

3.1 新版功能.

assertRegex(text, regex, msg=None)¶

assertNotRegex(text, regex, msg=None)¶

测试一个 regex 是否匹配 文本。如果不匹配，错误信息中将包含匹配模式和 文本*（或部分匹配失败的 *文本）。regex 可以是正则表达式对象或能够用于 re.search() 的包含正则表达式的字符串。

3.1 新版功能: 以方法名``assertRegexpMatches``添加。

在 3.2 版更改: 方法 assertRegexpMatches() 已被改名为 assertRegex()。

3.2 新版功能: assertNotRegex()

3.5 新版功能: assertNotRegexpMatches 这个名字是 assertNotRegex() 的已被弃用的别名。

assertCountEqual(first, second, msg=None)¶

Test that sequence first contains the same elements as second,

regardless of their order. When they don't, an error message listing the

differences between the sequences will be generated.

Duplicate elements are not ignored when comparing first and

second. It verifies whether each element has the same count in both

sequences. Equivalent to:

assertEqual(Counter(list(first)),Counter(list(second)))

but works with sequences of unhashable objects as well.

3.2 新版功能.

The assertEqual() method dispatches the equality check for objects of

the same type to different type-specific methods. These methods are already

implemented for most of the built-in types, but it's also possible to

register new methods using addTypeEqualityFunc():

addTypeEqualityFunc(typeobj, function)¶

Registers a type-specific method called by assertEqual() to check

if two objects of exactly the same typeobj (not subclasses) compare

equal. function must take two positional arguments and a third msg=None

keyword argument just as assertEqual() does. It must raise

self.failureException(msg) when inequality

between the first two parameters is detected -- possibly providing useful

information and explaining the inequalities in details in the error

message.

3.1 新版功能.

以下是 assertEqual() 自动选用的不同类型的比较方法。一般情况下不需要直接在测试中调用这些方法。

Method	用作比较	New in
assertMultiLineEqual(a,b)	字符串	3.1
assertSequenceEqual(a,b)	序列	3.1
assertListEqual(a,b)	列表	3.1
assertTupleEqual(a,b)	元组	3.1
assertSetEqual(a,b)	集合	3.1
assertDictEqual(a,b)	字典	3.1

assertMultiLineEqual(first, second, msg=None)¶

Test that the multiline string first is equal to the string second.

When not equal a diff of the two strings highlighting the differences

will be included in the error message. This method is used by default

when comparing strings with assertEqual().

3.1 新版功能.

assertSequenceEqual(first, second, msg=None, seq_type=None)¶

Tests that two sequences are equal. If a seq_type is supplied, both

first and second must be instances of seq_type or a failure will

be raised. If the sequences are different an error message is

constructed that shows the difference between the two.

This method is not called directly by assertEqual(), but

it's used to implement assertListEqual() and

assertTupleEqual().

3.1 新版功能.

assertListEqual(first, second, msg=None)¶

assertTupleEqual(first, second, msg=None)¶

Tests that two lists or tuples are equal. If not, an error message is

constructed that shows only the differences between the two. An error

is also raised if either of the parameters are of the wrong type.

These methods are used by default when comparing lists or tuples with

assertEqual().

3.1 新版功能.

assertSetEqual(first, second, msg=None)¶

Tests that two sets are equal. If not, an error message is constructed

that lists the differences between the sets. This method is used by

default when comparing sets or frozensets with assertEqual().

Fails if either of first or second does not have a set.difference()

method.

3.1 新版功能.

assertDictEqual(first, second, msg=None)¶

Test that two dictionaries are equal. If not, an error message is

constructed that shows the differences in the dictionaries. This

method will be used by default to compare dictionaries in

calls to assertEqual().

3.1 新版功能.

Finally the TestCase provides the following methods and attributes:

fail(msg=None)¶

Signals a test failure unconditionally, with msg or None for

the error message.

failureException¶

This class attribute gives the exception raised by the test method. If a

test framework needs to use a specialized exception, possibly to carry

additional information, it must subclass this exception in order to "play

fair" with the framework. The initial value of this attribute is

AssertionError.

longMessage¶

This class attribute determines what happens when a custom failure message

is passed as the msg argument to an assertXYY call that fails.

True is the default value. In this case, the custom message is appended

to the end of the standard failure message.

When set to False, the custom message replaces the standard message.

The class setting can be overridden in individual test methods by assigning

an instance attribute, self.longMessage, to True or False before

calling the assert methods.

The class setting gets reset before each test call.

3.1 新版功能.

maxDiff¶

This attribute controls the maximum length of diffs output by assert

methods that report diffs on failure. It defaults to 80*8 characters.

Assert methods affected by this attribute are

assertSequenceEqual() (including all the sequence comparison

methods that delegate to it), assertDictEqual() and

assertMultiLineEqual().

Setting maxDiff to None means that there is no maximum length of

diffs.

3.2 新版功能.

Testing frameworks can use the following methods to collect information on

the test:

countTestCases()¶

Return the number of tests represented by this test object. For

TestCase instances, this will always be 1.

defaultTestResult()¶

Return an instance of the test result class that should be used for this

test case class (if no other result instance is provided to the

run() method).

For TestCase instances, this will always be an instance of

TestResult; subclasses of TestCase should override this

as necessary.

id()¶

Return a string identifying the specific test case. This is usually the

full name of the test method, including the module and class name.

shortDescription()¶

Returns a description of the test, or None if no description

has been provided. The default implementation of this method

returns the first line of the test method's docstring, if available,

or None.

在 3.1 版更改: In 3.1 this was changed to add the test name to the short description

even in the presence of a docstring. This caused compatibility issues

with unittest extensions and adding the test name was moved to the

TextTestResult in Python 3.2.

addCleanup(function, *args, **kwargs)¶

Add a function to be called after tearDown() to cleanup resources

used during the test. Functions will be called in reverse order to the

order they are added (LIFO). They

are called with any arguments and keyword arguments passed into

addCleanup() when they are added.

If setUp() fails, meaning that tearDown() is not called,

then any cleanup functions added will still be called.

3.1 新版功能.

doCleanups()¶

This method is called unconditionally after tearDown(), or

after setUp() if setUp() raises an exception.

It is responsible for calling all the cleanup functions added by

addCleanup(). If you need cleanup functions to be called

prior to tearDown() then you can call doCleanups()

yourself.

doCleanups() pops methods off the stack of cleanup

functions one at a time, so it can be called at any time.

3.1 新版功能.

class unittest.FunctionTestCase(testFunc, setUp=None, tearDown=None, description=None)¶

This class implements the portion of the TestCase interface which

allows the test runner to drive the test, but does not provide the methods

which test code can use to check and report errors. This is used to create

test cases using legacy test code, allowing it to be integrated into a

unittest-based test framework.

Grouping tests¶

class unittest.TestSuite(tests=())¶

This class represents an aggregation of individual test cases and test suites.

The class presents the interface needed by the test runner to allow it to be run

as any other test case. Running a TestSuite instance is the same as

iterating over the suite, running each test individually.

If tests is given, it must be an iterable of individual test cases or other

test suites that will be used to build the suite initially. Additional methods

are provided to add test cases and suites to the collection later on.

TestSuite objects behave much like TestCase objects, except

they do not actually implement a test. Instead, they are used to aggregate

tests into groups of tests that should be run together. Some additional

methods are available to add tests to TestSuite instances:

addTest(test)¶

Add a TestCase or TestSuite to the suite.

addTests(tests)¶

Add all the tests from an iterable of TestCase and TestSuite

instances to this test suite.

This is equivalent to iterating over tests, calling addTest() for

each element.

TestSuite shares the following methods with TestCase:

run(result)¶

Run the tests associated with this suite, collecting the result into the

test result object passed as result. Note that unlike

TestCase.run(), TestSuite.run() requires the result object to

be passed in.

debug()¶

Run the tests associated with this suite without collecting the

result. This allows exceptions raised by the test to be propagated to the

caller and can be used to support running tests under a debugger.

countTestCases()¶

Return the number of tests represented by this test object, including all

individual tests and sub-suites.

__iter__()¶

Tests grouped by a TestSuite are always accessed by iteration.

Subclasses can lazily provide tests by overriding __iter__(). Note

that this method may be called several times on a single suite (for

example when counting tests or comparing for equality) so the tests

returned by repeated iterations before TestSuite.run() must be the

same for each call iteration. After TestSuite.run(), callers should

not rely on the tests returned by this method unless the caller uses a

subclass that overrides TestSuite._removeTestAtIndex() to preserve

test references.

在 3.2 版更改: In earlier versions the TestSuite accessed tests directly rather

than through iteration, so overriding __iter__() wasn't sufficient

for providing tests.

在 3.4 版更改: In earlier versions the TestSuite held references to each

TestCase after TestSuite.run(). Subclasses can restore

that behavior by overriding TestSuite._removeTestAtIndex().

In the typical usage of a TestSuite object, the run() method

is invoked by a TestRunner rather than by the end-user test harness.

Loading and running tests¶

class unittest.TestLoader¶

The TestLoader class is used to create test suites from classes and

modules. Normally, there is no need to create an instance of this class; the

unittest module provides an instance that can be shared as

unittest.defaultTestLoader. Using a subclass or instance, however,

allows customization of some configurable properties.

TestLoader objects have the following attributes:

errors¶

A list of the non-fatal errors encountered while loading tests. Not reset

by the loader at any point. Fatal errors are signalled by the relevant

a method raising an exception to the caller. Non-fatal errors are also

indicated by a synthetic test that will raise the original error when

run.

3.5 新版功能.

TestLoader objects have the following methods:

loadTestsFromTestCase(testCaseClass)¶

Return a suite of all test cases contained in the TestCase-derived

testCaseClass.

A test case instance is created for each method named by

getTestCaseNames(). By default these are the method names

beginning with test. If getTestCaseNames() returns no

methods, but the runTest() method is implemented, a single test

case is created for that method instead.

loadTestsFromModule(module, pattern=None)¶

Return a suite of all test cases contained in the given module. This

method searches module for classes derived from TestCase and

creates an instance of the class for each test method defined for the

class.

注解

While using a hierarchy of TestCase-derived classes can be

convenient in sharing fixtures and helper functions, defining test

methods on base classes that are not intended to be instantiated

directly does not play well with this method. Doing so, however, can

be useful when the fixtures are different and defined in subclasses.

If a module provides a load_tests function it will be called to

load the tests. This allows modules to customize test loading.

This is the load_tests protocol. The pattern argument is passed as

the third argument to load_tests.

在 3.2 版更改: Support for load_tests added.

在 3.5 版更改: The undocumented and unofficial use_load_tests default argument is

deprecated and ignored, although it is still accepted for backward

compatibility. The method also now accepts a keyword-only argument

pattern which is passed to load_tests as the third argument.

loadTestsFromName(name, module=None)¶

Return a suite of all test cases given a string specifier.

The specifier name is a "dotted name" that may resolve either to a

module, a test case class, a test method within a test case class, a

TestSuite instance, or a callable object which returns a

TestCase or TestSuite instance. These checks are

applied in the order listed here; that is, a method on a possible test

case class will be picked up as "a test method within a test case class",

rather than "a callable object".

For example, if you have a module SampleTests containing a

TestCase-derived class SampleTestCase with three test

methods (test_one(), test_two(), and test_three()), the

specifier 'SampleTests.SampleTestCase' would cause this method to

return a suite which will run all three test methods. Using the specifier

'SampleTests.SampleTestCase.test_two' would cause it to return a test

suite which will run only the test_two() test method. The specifier

can refer to modules and packages which have not been imported; they will

be imported as a side-effect.

The method optionally resolves name relative to the given module.

在 3.5 版更改: If an ImportError or AttributeError occurs while traversing

name then a synthetic test that raises that error when run will be

returned. These errors are included in the errors accumulated by

self.errors.

loadTestsFromNames(names, module=None)¶

Similar to loadTestsFromName(), but takes a sequence of names rather

than a single name. The return value is a test suite which supports all

the tests defined for each name.

getTestCaseNames(testCaseClass)¶

Return a sorted sequence of method names found within testCaseClass;

this should be a subclass of TestCase.

discover(start_dir, pattern='test*.py', top_level_dir=None)¶

Find all the test modules by recursing into subdirectories from the

specified start directory, and return a TestSuite object containing them.

Only test files that match pattern will be loaded. (Using shell style

pattern matching.) Only module names that are importable (i.e. are valid

Python identifiers) will be loaded.

All test modules must be importable from the top level of the project. If

the start directory is not the top level directory then the top level

directory must be specified separately.

If importing a module fails, for example due to a syntax error, then

this will be recorded as a single error and discovery will continue. If

the import failure is due to SkipTest being raised, it will be

recorded as a skip instead of an error.

If a package (a directory containing a file named __init__.py) is

found, the package will be checked for a load_tests function. If this

exists then it will be called

package.load_tests(loader,tests,pattern). Test discovery takes care

to ensure that a package is only checked for tests once during an

invocation, even if the load_tests function itself calls

loader.discover.

If load_tests exists then discovery does not recurse into the

package, load_tests is responsible for loading all tests in the

package.

The pattern is deliberately not stored as a loader attribute so that

packages can continue discovery themselves. top_level_dir is stored so

load_tests does not need to pass this argument in to

loader.discover().

start_dir can be a dotted module name as well as a directory.

3.2 新版功能.

在 3.4 版更改: Modules that raise SkipTest on import are recorded as skips,

not errors.

Discovery works for namespace packages.

Paths are sorted before being imported so that execution order is

the same even if the underlying file system's ordering is not

dependent on file name.

在 3.5 版更改: Found packages are now checked for load_tests regardless of

whether their path matches pattern, because it is impossible for

a package name to match the default pattern.

The following attributes of a TestLoader can be configured either by

subclassing or assignment on an instance:

testMethodPrefix¶

String giving the prefix of method names which will be interpreted as test

methods. The default value is 'test'.

This affects getTestCaseNames() and all the loadTestsFrom*()

methods.

sortTestMethodsUsing¶

Function to be used to compare method names when sorting them in

getTestCaseNames() and all the loadTestsFrom*() methods.

suiteClass¶

Callable object that constructs a test suite from a list of tests. No

methods on the resulting object are needed. The default value is the

TestSuite class.

This affects all the loadTestsFrom*() methods.

testNamePatterns¶

List of Unix shell-style wildcard test name patterns that test methods

have to match to be included in test suites (see -v option).

If this attribute is not None (the default), all test methods to be

included in test suites must match one of the patterns in this list.

Note that matches are always performed using fnmatch.fnmatchcase(),

so unlike patterns passed to the -v option, simple substring patterns

will have to be converted using * wildcards.

This affects all the loadTestsFrom*() methods.

3.7 新版功能.

class unittest.TestResult¶

This class is used to compile information about which tests have succeeded

and which have failed.

A TestResult object stores the results of a set of tests. The

TestCase and TestSuite classes ensure that results are

properly recorded; test authors do not need to worry about recording the

outcome of tests.

Testing frameworks built on top of unittest may want access to the

TestResult object generated by running a set of tests for reporting

purposes; a TestResult instance is returned by the

TestRunner.run() method for this purpose.

TestResult instances have the following attributes that will be of

interest when inspecting the results of running a set of tests:

errors¶

A list containing 2-tuples of TestCase instances and strings

holding formatted tracebacks. Each tuple represents a test which raised an

unexpected exception.

failures¶

A list containing 2-tuples of TestCase instances and strings

holding formatted tracebacks. Each tuple represents a test where a failure

was explicitly signalled using the TestCase.assert*() methods.

skipped¶

A list containing 2-tuples of TestCase instances and strings

holding the reason for skipping the test.

3.1 新版功能.

expectedFailures¶

A list containing 2-tuples of TestCase instances and strings

holding formatted tracebacks. Each tuple represents an expected failure

of the test case.

unexpectedSuccesses¶

A list containing TestCase instances that were marked as expected

failures, but succeeded.

shouldStop¶

Set to True when the execution of tests should stop by stop().

testsRun¶

The total number of tests run so far.

buffer¶

If set to true, sys.stdout and sys.stderr will be buffered in between

startTest() and stopTest() being called. Collected output will

only be echoed onto the real sys.stdout and sys.stderr if the test

fails or errors. Any output is also attached to the failure / error message.

3.2 新版功能.

failfast¶

If set to true stop() will be called on the first failure or error,

halting the test run.

3.2 新版功能.

tb_locals¶

If set to true then local variables will be shown in tracebacks.

3.5 新版功能.

wasSuccessful()¶

Return True if all tests run so far have passed, otherwise returns

False.

在 3.4 版更改: Returns False if there were any unexpectedSuccesses

from tests marked with the expectedFailure() decorator.

stop()¶

This method can be called to signal that the set of tests being run should

be aborted by setting the shouldStop attribute to True.

TestRunner objects should respect this flag and return without

running any additional tests.

For example, this feature is used by the TextTestRunner class to

stop the test framework when the user signals an interrupt from the

keyboard. Interactive tools which provide TestRunner

implementations can use this in a similar manner.

The following methods of the TestResult class are used to maintain

the internal data structures, and may be extended in subclasses to support

additional reporting requirements. This is particularly useful in building

tools which support interactive reporting while tests are being run.

startTest(test)¶

Called when the test case test is about to be run.

stopTest(test)¶

Called after the test case test has been executed, regardless of the

outcome.

startTestRun()¶

Called once before any tests are executed.

3.1 新版功能.

stopTestRun()¶

Called once after all tests are executed.

3.1 新版功能.

addError(test, err)¶

Called when the test case test raises an unexpected exception. err is a

tuple of the form returned by sys.exc_info(): (type,value,

traceback).

The default implementation appends a tuple (test,formatted_err) to

the instance's errors attribute, where formatted_err is a

formatted traceback derived from err.

addFailure(test, err)¶

Called when the test case test signals a failure. err is a tuple of

the form returned by sys.exc_info(): (type,value,traceback).

The default implementation appends a tuple (test,formatted_err) to

the instance's failures attribute, where formatted_err is a

formatted traceback derived from err.

addSuccess(test)¶

Called when the test case test succeeds.

The default implementation does nothing.

addSkip(test, reason)¶

Called when the test case test is skipped. reason is the reason the

test gave for skipping.

The default implementation appends a tuple (test,reason) to the

instance's skipped attribute.

addExpectedFailure(test, err)¶

Called when the test case test fails, but was marked with the

expectedFailure() decorator.

The default implementation appends a tuple (test,formatted_err) to

the instance's expectedFailures attribute, where formatted_err

is a formatted traceback derived from err.

addUnexpectedSuccess(test)¶

Called when the test case test was marked with the

expectedFailure() decorator, but succeeded.

The default implementation appends the test to the instance's

unexpectedSuccesses attribute.

addSubTest(test, subtest, outcome)¶

Called when a subtest finishes. test is the test case

corresponding to the test method. subtest is a custom

TestCase instance describing the subtest.

If outcome is None, the subtest succeeded. Otherwise,

it failed with an exception where outcome is a tuple of the form

returned by sys.exc_info(): (type,value,traceback).

The default implementation does nothing when the outcome is a

success, and records subtest failures as normal failures.

3.4 新版功能.

class unittest.TextTestResult(stream, descriptions, verbosity)¶

A concrete implementation of TestResult used by the

TextTestRunner.

3.2 新版功能: This class was previously named _TextTestResult. The old name still

exists as an alias but is deprecated.

unittest.defaultTestLoader¶

Instance of the TestLoader class intended to be shared. If no

customization of the TestLoader is needed, this instance can be used

instead of repeatedly creating new instances.

class unittest.TextTestRunner(stream=None, descriptions=True, verbosity=1, failfast=False, buffer=False, resultclass=None, warnings=None, *, tb_locals=False)¶

A basic test runner implementation that outputs results to a stream. If stream

is None, the default, sys.stderr is used as the output stream. This class

has a few configurable parameters, but is essentially very simple. Graphical

applications which run test suites should provide alternate implementations. Such

implementations should accept **kwargs as the interface to construct runners

changes when features are added to unittest.

By default this runner shows DeprecationWarning,

PendingDeprecationWarning, ResourceWarning and

ImportWarning even if they are ignored by default. Deprecation warnings caused by deprecated unittest

methods are also special-cased and, when the warning

filters are 'default' or 'always', they will appear only once

per-module, in order to avoid too many warning messages. This behavior can

be overridden using Python's -Wd or -Wa options

(see Warning control) and leaving

warnings to None.

在 3.2 版更改: Added the warnings argument.

在 3.2 版更改: The default stream is set to sys.stderr at instantiation time rather

than import time.

在 3.5 版更改: Added the tb_locals parameter.

_makeResult()¶

This method returns the instance of TestResult used by run().

It is not intended to be called directly, but can be overridden in

subclasses to provide a custom TestResult.

_makeResult() instantiates the class or callable passed in the

TextTestRunner constructor as the resultclass argument. It

defaults to TextTestResult if no resultclass is provided.

The result class is instantiated with the following arguments:

stream,descriptions,verbosity

run(test)¶

This method is the main public interface to the TextTestRunner. This

method takes a TestSuite or TestCase instance. A

TestResult is created by calling

_makeResult() and the test(s) are run and the

results printed to stdout.

unittest.main(module='__main__', defaultTest=None, argv=None, testRunner=None, testLoader=unittest.defaultTestLoader, exit=True, verbosity=1, failfast=None, catchbreak=None, buffer=None, warnings=None)¶

A command-line program that loads a set of tests from module and runs them;

this is primarily for making test modules conveniently executable.

The simplest use for this function is to include the following line at the

end of a test script:

if__name__=='__main__':
unittest.main()

You can run tests with more detailed information by passing in the verbosity

argument:

if__name__=='__main__':
unittest.main(verbosity=2)

The defaultTest argument is either the name of a single test or an

iterable of test names to run if no test names are specified via argv. If

not specified or None and no test names are provided via argv, all

tests found in module are run.

The argv argument can be a list of options passed to the program, with the

first element being the program name. If not specified or None,

the values of sys.argv are used.

The testRunner argument can either be a test runner class or an already

created instance of it. By default main calls sys.exit() with

an exit code indicating success or failure of the tests run.

The testLoader argument has to be a TestLoader instance,

and defaults to defaultTestLoader.

main supports being used from the interactive interpreter by passing in the

argument exit=False. This displays the result on standard output without

calling sys.exit():

>>> fromunittestimportmain
>>> main(module='test_module',exit=False)

The failfast, catchbreak and buffer parameters have the same

effect as the same-name command-line options.

The warnings argument specifies the warning filter

that should be used while running the tests. If it's not specified, it will

remain None if a -W option is passed to python

(see Warning control),

otherwise it will be set to 'default'.

Calling main actually returns an instance of the TestProgram class.

This stores the result of the tests run as the result attribute.

在 3.1 版更改: The exit parameter was added.

在 3.2 版更改: The verbosity, failfast, catchbreak, buffer

and warnings parameters were added.

在 3.4 版更改: The defaultTest parameter was changed to also accept an iterable of

test names.

load_tests(loader,standard_tests,pattern)

test_cases=(TestCase1,TestCase2,TestCase3)
defload_tests(loader,tests,pattern):
suite=TestSuite()
fortest_classintest_cases:
tests=loader.loadTestsFromTestCase(test_class)
suite.addTests(tests)
returnsuite

load_tests(loader,standard_tests,pattern)

defload_tests(loader,standard_tests,pattern):
# top level directory cached on loader instance
this_dir=os.path.dirname(__file__)
package_tests=loader.discover(start_dir=this_dir,pattern=pattern)
standard_tests.addTests(package_tests)
returnstandard_tests