1、標準異常

2.內置異常類的層次結構

BaseException
+-- SystemExit
+-- KeyboardInterrupt
+-- GeneratorExit
+-- Exception
+-- StopIteration
+-- ArithmeticError
| +-- FloatingPointError
| +-- OverflowError
| +-- ZeroDivisionError
+-- AssertionError
+-- AttributeError
+-- BufferError
+-- EOFError
+-- ImportError
+-- LookupError
| +-- IndexError
| +-- KeyError
+-- MemoryError
+-- NameError
| +-- UnboundLocalError
+-- OSError
| +-- BlockingIOError
| +-- ChildProcessError
| +-- ConnectionError
| | +-- BrokenPipeError
| | +-- ConnectionAbortedError
| | +-- ConnectionRefusedError
| | +-- ConnectionResetError
| +-- FileExistsError
| +-- FileNotFoundError
| +-- InterruptedError
| +-- IsADirectoryError
| +-- NotADirectoryError
| +-- PermissionError
| +-- ProcessLookupError
| +-- TimeoutError
+-- ReferenceError
+-- RuntimeError
| +-- NotImplementedError
+-- SyntaxError
| +-- IndentationError
| +-- TabError
+-- SystemError
+-- TypeError
+-- ValueError
| +-- UnicodeError
| +-- UnicodeDecodeError
| +-- UnicodeEncodeError
| +-- UnicodeTranslateError
+-- Warning
+-- DeprecationWarning
+-- PendingDeprecationWarning
+-- RuntimeWarning
+-- SyntaxWarning
+-- UserWarning
+-- FutureWarning
+-- ImportWarning
+-- UnicodeWarning
+-- BytesWarning
+-- ResourceWarning

3、異常處理

1.try語句

try:

　　檢測範圍

except Exception [as reason]:

　　出現Exception後處理的代碼

可以有多個except與try組合，因為檢測範圍中肯能會產生多個異常，可以用多個except與try組合來關註感興趣的異常

可以同一處理多類異常 except後要用()把多個需要同一處理的異常括起來

try:
    int(‘abc‘)
    sum = 1+‘1‘ 
    f = open(‘我是一個不存在的文檔.txt‘)
    print(f.read())
    f.close()
except (OSError, ValueError,TypeError)as reason:
    print(‘出錯啦T_T\n錯誤原因是：‘ + str(reason))

2.try finally語句

try:

　　檢測範圍

except Exception [as reason]:

　　出現Exception後處理的代碼

finally:

　　一定要做的事情（比如出錯後可以在這裏把文件關閉）

try:
    f = open(‘My_File.txt‘) # 當前文件夾中並不存在"My_File.txt"這個文件T_T
    print(f.read())
except OSError as reason:
    print(‘出錯啦：‘ + str(reason))
finally:
    if ‘f‘ in locals(): # 如果文件對象變量存在當前局部變量符號表的話，說明打開成功
        f.close()

3、raise語句（引發一個異常）

raise 異常名字

try:
    for i in range(3):
        for j in range(3):
            if i == 2:
                raise KeyboardInterrupt
            print(i, j)
except KeyboardInterrupt:
    print(‘退出啦！‘)

Python3 異常檢測