try:
 <statements>  #運行try語句塊，并試圖捕獲異常
except <name1>:
 <statements>  #如果name1異常發(fā)現，那么執(zhí)行該語句塊。
except (name2, name3):
 <statements>  #如果元組內的任意異常發(fā)生，那么捕獲它
except <name4> as <variable>:
 <statements>  #如果name4異常發(fā)生，那么進入該語句塊，并把異常實例命名為variable
except:
 <statements>  #發(fā)生了以上所有列出的異常之外的異常
else:
<statements>   #如果沒有異常發(fā)生，那么執(zhí)行該語句塊
finally:
 <statement>   #無論是否有異常發(fā)生，均會執(zhí)行該語句塊。

try:
 1/0
except Exception as E:
 raise TypeError('bad input') from E

Traceback (most recent call last):
 File "hh.py", line 2, in <module>
 1/0
ZeroDivisionError: division by zero

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
 File "hh.py", line 4, in <module>
 raise TypeError('bad input') from E
TypeError: bad input

class Block:
 def __enter__(self):
  print('entering to the block')
  return self
 
 def prt(self, args):
  print('this is the block we do %s' % args)

 def __exit__(self,exc_type, exc_value, exc_tb):
  if exc_type is None:
   print('exit normally without exception')
  else:
   print('found exception: %s, and detailed info is %s' % (exc_type, exc_value))
  return False

with Block() as b:
 b.prt('actual work!')
 raise ValueError('wrong')

entering to the block
this is the block we do actual work!
found exception: <class 'ValueError'>, and detailed info is wrong
Traceback (most recent call last):
 File "hh.py", line 18, in <module>
 raise ValueError('wrong')
ValueError: wrong

|Exception Name|Description|
|BaseException|Root class for all exceptions|
| SystemExit|Request termination of Python interpreter|
|KeyboardInterrupt|User interrupted execution (usually by pressing Ctrl+C)|
|Exception|Root class for regular exceptions|
| StopIteration|Iteration has no further values|
| GeneratorExit|Exception sent to generator to tell it to quit|
| SystemExit|Request termination of Python interpreter|
| StandardError|Base class for all standard built-in exceptions|
|  ArithmeticError|Base class for all numeric calculation errors|
|   FloatingPointError|Error in floating point calculation|
|   OverflowError|Calculation exceeded maximum limit for numerical type|
|   ZeroDivisionError|Division (or modulus) by zero error (all numeric types)|
|  AssertionError|Failure of assert statement|
|  AttributeError|No such object attribute|
|  EOFError|End-of-file marker reached without input from built-in|
|  EnvironmentError|Base class for operating system environment errors|
|   IOError|Failure of input/output operation|
|   OSError|Operating system error|
|    WindowsError|MS Windows system call failure|
|    ImportError|Failure to import module or object|
|    KeyboardInterrupt|User interrupted execution (usually by pressing Ctrl+C)|
|   LookupError|Base class for invalid data lookup errors|
|    IndexError|No such index in sequence|
|    KeyError|No such key in mapping|
|   MemoryError|Out-of-memory error (non-fatal to Python interpreter)|
|   NameError|Undeclared/uninitialized object(non-attribute)|
|    UnboundLocalError|Access of an uninitialized local variable|
|   ReferenceError|Weak reference tried to access a garbage collected object|
|   RuntimeError|Generic default error during execution|
|    NotImplementedError|Unimplemented method|
|   SyntaxError|Error in Python syntax|
|    IndentationError|Improper indentation|
|     TabErrorg|Improper mixture of TABs and spaces|
|   SystemError|Generic interpreter system error|
|   TypeError|Invalid operation for type|
|   ValueError|Invalid argument given|
|    UnicodeError|Unicode-related error|
|     UnicodeDecodeError|Unicode error during decoding|
|     UnicodeEncodeError|Unicode error during encoding|
|     UnicodeTranslate Error|Unicode error during translation|
|  Warning|Root class for all warnings|
|   DeprecationWarning|Warning about deprecated features|
|   FutureWarning|Warning about constructs that will change semantically in the future|
|   OverflowWarning|Old warning for auto-long upgrade|
|   PendingDeprecation Warning|Warning about features that will be deprecated in the future|
|   RuntimeWarning|Warning about dubious runtime behavior|
|   SyntaxWarning|Warning about dubious syntax|
|   UserWarning|Warning generated by user code|