python 几种常见的测试框架

1. unittest

参考文档： https://docs.python.org/3/library/unittest.html

unittest笔记

The unittest unit testing framework was originally inspired by JUnit and has a similar flavor as major unit testing frameworks in other languages. It supports test automation, sharing of setup and shutdown code for tests, aggregation of tests into collections, and independence of the tests from the reporting framework.

unittest 和 JUnit类似，可以说是python的标准单元测试框架，所以有时也被人称为 PyUnit。它使用起来和xUnit 家族其他成员类似。 用的人也比较多。兼容 python2 以及python3 。

个人比较喜欢用这个，主要之前用过JUnit，用这个上手就很快。而且属于python自动集成，不用额外的安装包，感觉是该有的都有了，用着方便。

官网示例：

import unittest

class TestStringMethods(unittest.TestCase):

    def test_upper(self):
        self.assertEqual('foo'.upper(), 'FOO')

    def test_isupper(self):
        self.assertTrue('FOO'.isupper())
        self.assertFalse('Foo'.isupper())

    def test_split(self):
        s = 'hello world'
        self.assertEqual(s.split(), ['hello', 'world'])
        # check that s.split fails when the separator is not a string
        with self.assertRaises(TypeError):
            s.split(2)

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

2. unittest2

参考文档： https://pypi.python.org/pypi/unittest2

unittest2 is a backport of the new features added to the unittest testing framework in Python 2.7 and onwards.

unittest2 可以说是一个针对 unittest测试框架新特性的补丁。它很大程度上和unittest都类似。然后还添加了一些unittest没有的方法。

3. pytest

参考文档：http://pytest.org/latest/

The pytest framework makes it easy to write small tests, yet scales to support complex functional testing for applications and libraries.

看了一下，pytest文档还是蛮详细的。比较关注的一点是，pytest 直接可以通过 @pytest.mark.parametrize 进行参数化，而unittest 则需要借助DDT。

官网示例：

# content of test_sample.py
def inc(x):
    return x + 1

def test_answer():
    assert inc(3) == 5

执行如下：

$ pytest
======= test session starts ========
platform linux -- Python 3.x.y, pytest-3.x.y, py-1.x.y, pluggy-0.x.y
rootdir: $REGENDOC_TMPDIR, inifile:
collected 1 item

test_sample.py F

======= FAILURES ========
_______ test_answer ________

    def test_answer():
>       assert inc(3) == 5
E       assert 4 == 5
E        +  where 4 = inc(3)

test_sample.py:5: AssertionError
======= 1 failed in 0.12 seconds ========

4. nose

参考文档： https://nose.readthedocs.org/en/latest/

基于Python的测试驱动开发实战 也有nose的用法： http://python.jobbole.com/81305/

nose extends unittest to make testing easier.

nose扩展了unittest，从而使得测试更容易。

一般可以用unittest方式写用例，写完之后用nose来执行。nose的测试收集方式还是很方便的。

 还有一个特定就是，nose可以采用  @with_setup() 来定义方法的setup和teardown。

 官方示例：

def setup_func():
    "set up test fixtures"

def teardown_func():
    "tear down test fixtures"

@with_setup(setup_func, teardown_func)
def test():
    "test ..."

5. doctest

参考文档：https://docs.python.org/3/library/doctest.html

Python 各种测试框架简介（一）：doctest  http://my.oschina.net/lionets/blog/268542

The doctest module searches for pieces of text that look like interactive Python sessions, and then executes those sessions to verify that they work exactly as shown.

doctest模块会搜索那些看起来像交互式会话的 Python 代码片段，然后尝试执行并验证结果。

doctest 中，如果要写测试用例，只需要在写在以 ''' '''包围的文档注释即可，也就是可以被__doc__这个属性引用到的地方。这点比较特别，跟其他单元测试框架都不一样。但是我觉得这样的话就注定了doctest不适合大型测试，因为做不到代码和测试的分离。

import doctest

"""
This is the "example" module.

The example module supplies one function, factorial().  For example,

>>> factorial(5)
120
"""

def factorial(n):
    """Return the factorial of n, an exact integer >= 0.

    >>> [factorial(n) for n in range(6)]
    [1, 1, 2, 6, 24, 120]
    >>> factorial(30)
    265252859812191058636308480000000
    >>> factorial(-1)
    Traceback (most recent call last):
        ...
    ValueError: n must be >= 0

    Factorials of floats are OK, but the float must be an exact integer:
    >>> factorial(30.1)
    Traceback (most recent call last):
        ...
    ValueError: n must be exact integer
    >>> factorial(30.0)
    265252859812191058636308480000000

    It must also not be ridiculously large:
    >>> factorial(1e100)
    Traceback (most recent call last):
        ...
    OverflowError: n too large
    """

    import math
    if not n >= 0:
        raise ValueError("n must be >= 0")
    if math.floor(n) != n:
        raise ValueError("n must be exact integer")
    if n+1 == n:  # catch a value like 1e300
        raise OverflowError("n too large")
    result = 1
    factor = 2
    while factor <= n:
        result *= factor
        factor += 1
    return result


if __name__ == "__main__":
    doctest.testmod(verbose=True)

verbose 参数用于控制是否输出详细信息，默认为 False ，如果不写，那么运行时不会输出任何东西，除非测试 fail。

输出如下：

Trying:
    [factorial(n) for n in range(6)]
Expecting:
    [1, 1, 2, 6, 24, 120]
ok
Trying:
    factorial(30)
Expecting:
    265252859812191058636308480000000
ok
Trying:
    factorial(-1)
Expecting:
    Traceback (most recent call last):
        ...
    ValueError: n must be >= 0
ok
Trying:
    factorial(30.1)
Expecting:
    Traceback (most recent call last):
        ...
    ValueError: n must be exact integer
ok
Trying:
    factorial(30.0)
Expecting:
    265252859812191058636308480000000
ok
Trying:
    factorial(1e100)
Expecting:
    Traceback (most recent call last):
        ...
    OverflowError: n too large
ok
1 items had no tests:
    __main__
1 items passed all tests:
   6 tests in __main__.factorial
6 tests in 2 items.
6 passed and 0 failed.
Test passed.