Question

我需要查看异常层次结构，并使其显示良好，如here所示。

在终端上，我得到了以字母顺序显示的那些内置异常（以及其他内容）：

>>> import pprint
>>> pprint.pprint(dir(__builtins__))

知道BaseException是所有现有异常的基类，你知道如何实现这个目标吗？

修改

如果需要：How to find all the subclasses of a class given its name?

Answer 1

def print_classes(cls, indent):
    print('{}{}'.format(indent, cls.__name__))
    for sc in cls.__subclasses__():
        print_classes(sc, indent + "  ")


print_classes((BaseException),'')

Answer 2

这是一个部分解决方案，为您提供了一个源于什么的字典。

为了打造更漂亮的印刷品，您必须自己做一些事情：

import inspect

l = [eval(x) for x in dir(__builtins__) if inspect.isclass(eval(x)) and issubclass(eval(x),BaseException)]

d = {}

for err in l:
    d[err] = err.__subclasses__()

import pprint
pprint.pprint(d)

输出：

{<class 'ResourceWarning'>: [],
 <class 'BytesWarning'>: [],
 <class 'UnicodeWarning'>: [],
 <class 'ImportWarning'>: [],
 <class 'FutureWarning'>: [],
 <class 'RuntimeWarning'>: [],
 <class 'SyntaxWarning'>: [],
 <class 'PendingDeprecationWarning'>: [],
 <class 'DeprecationWarning'>: [],
 <class 'UserWarning'>: [],
 <class 'Warning'>: [<class 'UserWarning'>,
                     <class 'DeprecationWarning'>,
                     <class 'PendingDeprecationWarning'>,
                     <class 'SyntaxWarning'>,
                     <class 'RuntimeWarning'>,
                     <class 'FutureWarning'>,
                     <class 'ImportWarning'>,
                     <class 'UnicodeWarning'>,
                     <class 'BytesWarning'>,
                     <class 'ResourceWarning'>],
 <class 'BufferError'>: [],
 <class 'MemoryError'>: [],
 <class 'ReferenceError'>: [],
 <class 'SystemError'>: [<class 'encodings.CodecRegistryError'>],
 <class 'ZeroDivisionError'>: [],
 <class 'OverflowError'>: [],
 <class 'FloatingPointError'>: [],
 <class 'ArithmeticError'>: [<class 'FloatingPointError'>,
                             <class 'OverflowError'>,
                             <class 'ZeroDivisionError'>],
 <class 'AssertionError'>: [],
 <class 'UnicodeTranslateError'>: [],
 <class 'UnicodeDecodeError'>: [],
 <class 'UnicodeEncodeError'>: [],
 <class 'UnicodeError'>: [<class 'UnicodeEncodeError'>,
                          <class 'UnicodeDecodeError'>,
                          <class 'UnicodeTranslateError'>],
 <class 'ValueError'>: [<class 'UnicodeError'>,
                        <class 'io.UnsupportedOperation'>],
 <class 'KeyError'>: [],
 <class 'IndexError'>: [],
 <class 'LookupError'>: [<class 'IndexError'>,
                         <class 'KeyError'>,
                         <class 'encodings.CodecRegistryError'>],
 <class 'TabError'>: [],
 <class 'IndentationError'>: [<class 'TabError'>],
 <class 'SyntaxError'>: [<class 'IndentationError'>],
 <class 'AttributeError'>: [],
 <class 'UnboundLocalError'>: [],
 <class 'NameError'>: [<class 'UnboundLocalError'>],
 <class 'NotImplementedError'>: [],
 <class 'RecursionError'>: [],
 <class 'RuntimeError'>: [<class 'RecursionError'>,
                          <class 'NotImplementedError'>,
                          <class '_frozen_importlib._DeadlockError'>],
 <class 'EOFError'>: [],
 <class 'TimeoutError'>: [],
 <class 'ProcessLookupError'>: [],
 <class 'PermissionError'>: [],
 <class 'InterruptedError'>: [],
 <class 'NotADirectoryError'>: [],
 <class 'IsADirectoryError'>: [],
 <class 'FileNotFoundError'>: [],
 <class 'FileExistsError'>: [],
 <class 'ConnectionResetError'>: [],
 <class 'ConnectionRefusedError'>: [],
 <class 'ConnectionAbortedError'>: [],
 <class 'BrokenPipeError'>: [],
 <class 'ChildProcessError'>: [],
 <class 'ConnectionError'>: [<class 'BrokenPipeError'>,
                             <class 'ConnectionAbortedError'>,
                             <class 'ConnectionRefusedError'>,
                             <class 'ConnectionResetError'>],
 <class 'BlockingIOError'>: [],
 <class 'OSError'>: [<class 'ConnectionError'>,
                     <class 'BlockingIOError'>,
                     <class 'ChildProcessError'>,
                     <class 'FileExistsError'>,
                     <class 'FileNotFoundError'>,
                     <class 'IsADirectoryError'>,
                     <class 'NotADirectoryError'>,
                     <class 'InterruptedError'>,
                     <class 'PermissionError'>,
                     <class 'ProcessLookupError'>,
                     <class 'TimeoutError'>,
                     <class 'io.UnsupportedOperation'>,
                     <class 'signal.ItimerError'>],
 <class 'ModuleNotFoundError'>: [],
 <class 'ImportError'>: [<class 'ModuleNotFoundError'>,
                         <class 'zipimport.ZipImportError'>],
 <class 'KeyboardInterrupt'>: [],
 <class 'SystemExit'>: [],
 <class 'GeneratorExit'>: [],
 <class 'StopIteration'>: [],
 <class 'StopAsyncIteration'>: [],
 <class 'TypeError'>: [],
 <class 'Exception'>: [<class 'TypeError'>,
                       <class 'StopAsyncIteration'>,
                       <class 'StopIteration'>,
                       <class 'ImportError'>,
                       <class 'OSError'>,
                       <class 'EOFError'>,
                       <class 'RuntimeError'>,
                       <class 'NameError'>,
                       <class 'AttributeError'>,
                       <class 'SyntaxError'>,
                       <class 'LookupError'>,
                       <class 'ValueError'>,
                       <class 'AssertionError'>,
                       <class 'ArithmeticError'>,
                       <class 'SystemError'>,
                       <class 'ReferenceError'>,
                       <class 'BufferError'>,
                       <class 'MemoryError'>,
                       <class 'Warning'>,
                       <class 'locale.Error'>,
                       <class 'warnings._OptionError'>,
                       <class 'sre_constants.error'>,
                       <class 'sre_parse.Verbose'>,
                       <class 'tokenize.TokenError'>,
                       <class 'tokenize.StopTokenizing'>,
                       <class 'inspect.EndOfBlock'>],
 <class 'BaseException'>: [<class 'Exception'>,
                           <class 'GeneratorExit'>,
                           <class 'SystemExit'>,
                           <class 'KeyboardInterrupt'>]}

如何在Python中显示内置异常层次结构？

2 个答案: