Testing 

– Unit testing: Individual units or components of a program are tested
-Integration testing: Individual units are combined and tested as a group
-System testing: The complete integrated application is tested as a whole
-Acceptance testing: The complete application is tested by users before its deployment

– Valid/Invalid/Boundary test cases
Based upon “correct” input data
Based upon “incorrect” input data
Boundary values of the “equivalence class” for valid cases


– Debugging: print, assert



Exceptions and errors
---Syntax errors: cannot be understood by the compiler/interpreter
---Run-time errors: Occur during execution; errors that are anticipated and can be dealt with 
appropriately 
---Logic errors: Incorrect implementation of the program’s logic
– Exception handling: 



▪ try except
▪ else finally

Else和finally是可有可无的，不管情况如何都要执行finally的内容