Keywords assert constitute assertion, mainly when we can write a new program, you can use it to help us lock bug range.
expression:
assert expression 'window prompt information'
The project parentheses are optional items, optional items will be thrown in the Boolean expression is False, it causes errors more clearly.
E.g:
A =. 5 >>>
>>> = B. 6
>>> Assert A> B, 'A is not greater than B'
Traceback (MOST Recent Last Call):
File "<pyshell # 26 is>", Line. 1, in <Module1>
assert a> b, 'a no greater than b'
AssertionError with: b is not greater than A
Similarly, we can also use the function code that implements assert statement:
E.g:
if not the expression:
raise message
>>> a = 5
>>> b = 6
>>> if a < b:
raise 'a不大于b'
>>> b = 6
>>> if a < b:
raise 'a不大于b'
Traceback (most recent call last):
File "<pyshell#31>", line 2, in <module>
raise 'a不大于b'
TypeError: exceptions must derive from BaseException
>>> if a > b :
raise 'fadsfas'
File "<pyshell#31>", line 2, in <module>
raise 'a不大于b'
TypeError: exceptions must derive from BaseException
>>> if a > b :
raise 'fadsfas'
>>>
for reference only!