python doctest测试

---

title: Python doctest测试
tags: Python
---

doctest测试

python 提供了REPL（read-eval-print loop，读取、求值、输出的循环）

官方地址：https://docs.python.org/3/library/doctest.html

"""
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 >= 0Factorials 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)265252859812191058636308480000000It must also not be ridiculously large:>>> factorial(1e100)Traceback (most recent call last):...OverflowError: n too large"""import mathif 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 1e300raise OverflowError("n too large")result = 1factor = 2while factor <= n:result *= factorfactor += 1return resultif __name__ == "__main__":import doctestdoctest.testmod()

执行Python3 test.py -v

结果：

Trying:factorial(5)
Expecting:120
ok
Trying:[factorial(n) for n in range(6)]
Expecting:[1, 1, 2, 6, 24, 120]
ok
Trying:factorial(30)
Expecting:265252859812191058636308480000000
**********************************************************************
File "test.py", line 15, in __main__.factorial
Failed example:factorial(30)
Expected:265252859812191058636308480000000
Got:265252859812191058636308480000000L
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
**********************************************************************
File "test.py", line 27, in __main__.factorial
Failed example:factorial(30.0)
Expected:265252859812191058636308480000000
Got:265252859812191058636308480000000L
Trying:factorial(1e100)
Expecting:Traceback (most recent call last):...OverflowError: n too large
ok
1 items passed all tests:1 tests in __main__
**********************************************************************
1 items had failures:2 of   6 in __main__.factorial
7 tests in 2 items.
5 passed and 2 failed.
***Test Failed*** 2 failures.