Python3 exception detection and Python3 Detection

Python3 exception detection and Python3 Detection
1. Standard exceptions

AssertionError	Assert failure
AttributeError	Attempt to access unknown object properties
EOFError	Mark at the end of the user input file: EOF (Ctrl + d)
FloatingPointError	Floating Point Calculation Error
GeneratorExit	When the generator. close () method is called
ImportError	When the import module fails
IndexError	The index is out of the range of the sequence.
KeyError	Search for a non-existent keyword in the dictionary
KeyboardInterrupt	User input interrupt key (Ctrl + c)
MemoryError	Memory overflow (memory can be released by deleting objects)
NameError	Try to access a non-existent variable
NotImplementedError	Unimplemented Methods
OSError	Operating system exceptions (for example, opening a non-existent file)
OverflowError	The value operation exceeds the maximum limit.
ReferenceError	Weak reference attempts to access an object that has been recycled by the garbage collection mechanism.
RuntimeError	General running errors
StopIteration	The iterator does not have more values.
SyntaxError	Python syntax error
IndentationError	Indentation Error
TabError	Mixed Use of Tab and Space
SystemError	Python Compiler System Error
SystemExit	The Python compiler process is disabled.
TypeError	Invalid operation between different types
UnboundLocalError	Access an uninitialized local variable (subclass of NameError)
UnicodeError	Unicode errors (subclass of ValueError)
UnicodeEncodeError	Unicode encoding error (subclass of UnicodeError)
UnicodeDecodeError	Unicode decoding error (subclass of UnicodeError)
UnicodeTranslateError	Unicode Conversion error (subclass of UnicodeError)
ValueError	Invalid parameter passed in
ZeroDivisionError	Division zero

2. built-in exception class hierarchy

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. Exception Handling 1. try statement

Try:

Detection scope

Failed t Exception [as reason]:

Code after Exception Processing

 

There can be a combination of multiple consumer T and try, because the detection range will certainly produce multiple exceptions, you can use multiple consumer T and try combinations to focus on exceptions of interest.

You can use () to enclose multiple exceptions that need to be processed in the same way after handling multiple types of exceptions.

try:
     int ('abc')
     sum = 1 + '1'
     f = open ('I am a non-existing document.txt')
     print (f.read ())
     f.close ()
except (OSError, ValueError, TypeError) as reason:
     print ('Error T_T \ nThe reason for the error is:' + str (reason))

2. try finally statement

Try:

Detection scope

Failed t Exception [as reason]:

Code after Exception Processing

Finally:

Something to do (for example, you can close the file here after an error occurs)

try:
     f = open ('My_File.txt') # The file "My_File.txt" does not exist in the current folder T_T
     print (f.read ())
except OSError as reason:
     print ('Error:' + str (reason))
finally:
     if 'f' in locals (): # If the file object variable exists in the current local variable symbol table, it means that the opening was successful
         f.close ()

3. raise Statement (throwing an exception)

Raise Exception name

try:
     for i in range (3):
         for j in range (3):
             if i == 2:
                 raise KeyboardInterrupt
             print (i, j)
except KeyboardInterrupt:
     print ('Exit!')