Python assert断言

根据Python 官方文档解释(https://docs.python.org/3/reference/simple_stmts.html#assert), "Assert statements are a convenient way to insert debugging assertions into a program".

一般的用法是：

assert condition

用来让程序测试这个condition，如果condition为false，那么raise一个AssertionError出来。逻辑上等同于：

if not condition:
    raise AssertionError()

比如如下的例子：

>>> assert 1==1
>>> assert 1==0
Traceback (most recent call last):
  File "<pyshell#1>", line 1, in <module>
    assert 1==0
AssertionError
>>> assert True
>>> assert False
Traceback (most recent call last):
  File "<pyshell#3>", line 1, in <module>
    assert False
AssertionError
>>> assert 3<2
Traceback (most recent call last):
  File "<pyshell#4>", line 1, in <module>
    assert 3<2
AssertionError