try block without exception, executes else
Regardless of whether the abnormal finally, will be executed
Active trigger abnormal raise TypeEroor ()
Custom exception
断言 assert条件——》assert res1 = 1 ——》if res1 !=1 raise AssertionError
When exception handling with: Only in some abnormal unforeseen circumstances, it should be added to try. . . except, other logical errors should be corrected as much as possible.
