异常处理及反射_opcpackage.open异常-优快云博客

****反射****

#dir(obj,property|method)列出对象的属性名和方法名
#hasatter(obj,property|method)判断是否存在属性和方法
#getatter(obj,property|method,default)调用属性或方法
#setatter(obj,property|method,new)修改属性或方法

class MyOpen(object):
    def __init__(self, filename, mode='r'):
        self.name = filename
        self.mode = mode

    def get_name(self):
        a = 2
        print("get name info name......", end=' ')
        return self.name

    def get_mode(self):
        return self.mode


open1 = MyOpen('/etc/passwd')
open2 = MyOpen('/etc/passwd')

print(dir(open1))
print(hasattr(open1, 'name'))
print(hasattr(open1, 'get_name'))

print(getattr(open1, 'name'))
print(getattr(open1, 'get_name')())


def aa():
    return "this is add functions"


setattr(open1, 'name', 'sr132')
print(getattr(open1, 'name'))
setattr(open1, 'get_name', aa)
print(getattr(open1, 'get_name')())

#def __exit__(self, exc_type, exc_val, exc_tb):

# self.f.close()

类里面实现with语句

****异常处理****

try：

xxxxx尝试某操作

except xxx：

xxxxx出现某错误执行

finally：

xxxxx无论报不报错都执行

raise xxxxx抛出该错误

异常类：

BaseException
+-- SystemExit
+-- KeyboardInterrupt
+-- GeneratorExit
+-- Exception
      +-- StopIteration
      +-- StopAsyncIteration
      +-- ArithmeticError
      |    +-- FloatingPointError
      |    +-- OverflowError
      |    +-- ZeroDivisionError
      +-- AssertionError
      +-- AttributeError
      +-- BufferError
      +-- EOFError
      +-- ImportError
      |    +-- ModuleNotFoundError
      +-- 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
      |    +-- RecursionError
      +-- SyntaxError
      |    +-- IndentationError
      |         +-- TabError
      +-- SystemError
      +-- TypeError
      +-- ValueError
      |    +-- UnicodeError
      |         +-- UnicodeDecodeError
      |         +-- UnicodeEncodeError
      |         +-- UnicodeTranslateError
      +-- Warning
           +-- DeprecationWarning
           +-- PendingDeprecationWarning
           +-- RuntimeWarning
           +-- SyntaxWarning
           +-- UserWarning
           +-- FutureWarning
           +-- ImportWarning
           +-- UnicodeWarning
           +-- BytesWarning
           +-- ResourceWarning