1.使用assert声明方法
# define a function to test
def fib(x):
if x==0:
return 0
elif x==1:
return 1
else:
return fib(x-1)+fib(x-2)
# define a test function
def fib_test():
assert fib(2) == 1, 'The 2nd Fibonacci number should be 1'
assert fib(3) == 1, 'The 3rd Fibonacci number should be 1'
assert fib(50) == 7778742049, 'Error at the 50th Fibonacci number'
# execute test
fib_test(2)
fib_test()函数会先执行fib()函数，然后与assert命令的指标进行对比，如果不符就会报错。
2.使用run_docstring_examples函数
def sum_naturals(n):
"""Return the sum of the first n natural numbers.
>>> sum_naturals(10)
55
>>> sum_naturals(100)
5050
"""
total, k = 0, 1
while k <= n:
total, k = total + k, k + 1
return total
from doctest import run_docstring_examples
run_docstring_examples(sum_naturals,globals(),True)
函数sum_naturals()在声明时使用三个引号提供了一份简单的说明。在编译器中执行help()函数皆可获得这段说明（按Q退出）。同时，这份说明也指出了特定之下的输出值。利用run_docstring_examples函数可以自动完成检验，并输出检验结果。例如,
Trying:
sum_naturals(10)
Expecting:
55
ok
Trying:
sum_naturals(100)
Expecting:
5050
ok
