"""Python's standard exception class hierarchy. Before Python 1.5, the standard exceptions were all simple string objects. In Python 1.5, the standard exceptions were converted to classes organized into a relatively flat hierarchy. String-based standard exceptions were optional, or used as a fallback if some problem occurred while importing the exception module. With Python 1.6, optional string-based standard exceptions were removed (along with the -X command line flag). The class exceptions were implemented in such a way as to be almost completely backward compatible. Some tricky uses of IOError could potentially have broken, but by Python 1.6, all of these should have been fixed. As of Python 1.6, the class-based standard exceptions are now implemented in C, and are guaranteed to exist in the Python interpreter. Here is a rundown of the class hierarchy. The classes found here are inserted into both the exceptions module and the `built-in' module. It is recommended that user defined class based exceptions be derived from the `Exception' class, although this is currently not enforced. BaseException +-- SystemExit +-- KeyboardInterrupt +-- Exception +-- GeneratorExit +-- StopIteration +-- StandardError | +-- ArithmeticError | | +-- FloatingPointError | | +-- OverflowError | | +-- ZeroDivisionError | +-- AssertionError | +-- AttributeError | +-- EnvironmentError | | +-- IOError | | +-- OSError | | +-- WindowsError (Windows) | | +-- VMSError (VMS) | +-- EOFError | +-- ImportError | +-- LookupError | | +-- IndexError | | +-- KeyError | +-- MemoryError | +-- NameError | | +-- UnboundLocalError | +-- ReferenceError | +-- RuntimeError | | +-- NotImplementedError | +-- SyntaxError | | +-- IndentationError | | +-- TabError | +-- SystemError | +-- TypeError | +-- ValueError | | +-- UnicodeError | | +-- UnicodeDecodeError | | +-- UnicodeEncodeError | | +-- UnicodeTranslateError +-- Warning +-- DeprecationWarning +-- PendingDeprecationWarning +-- RuntimeWarning +-- SyntaxWarning +-- UserWarning +-- FutureWarning +-- ImportWarning +-- UnicodeWarning """ from pypy.interpreter.baseobjspace import ObjSpace, Wrappable, W_Root from pypy.interpreter.typedef import TypeDef, interp_attrproperty_w,\ GetSetProperty, interp_attrproperty, descr_get_dict, descr_set_dict,\ descr_del_dict from pypy.interpreter.gateway import interp2app, Arguments from pypy.interpreter.error import OperationError from pypy.rlib import rwin32 def readwrite_attrproperty_w(name, cls): def fget(space, obj): return getattr(obj, name) def fset(space, obj, w_val): setattr(obj, name, w_val) return GetSetProperty(fget, fset, cls=cls) class W_BaseException(Wrappable): """Superclass representing the base of the exception hierarchy. The __getitem__ method is provided for backwards-compatibility and will be deprecated at some point. """ w_dict = None args_w = [] def __init__(self, space): self.space = space self.w_message = space.w_None def descr_init(self, space, args_w): self.args_w = args_w if len(args_w) == 1: self.w_message = args_w[0] else: self.w_message = space.wrap("") descr_init.unwrap_spec = ['self', ObjSpace, 'args_w'] def descr_str(self, space): lgt = len(self.args_w) if lgt == 0: return space.wrap('') elif lgt == 1: return space.str(self.args_w[0]) else: return space.str(space.newtuple(self.args_w)) descr_str.unwrap_spec = ['self', ObjSpace] def descr_repr(self, space): if self.args_w: args_repr = space.str_w(space.repr(space.newtuple(self.args_w))) else: args_repr = "()" clsname = self.getclass(space).getname(space, '?') return space.wrap(clsname + args_repr) descr_repr.unwrap_spec = ['self', ObjSpace] def descr_getargs(space, self): return space.newtuple(self.args_w) def descr_setargs(space, self, w_newargs): self.args_w = space.fixedview(w_newargs) def descr_getitem(self, space, w_index): return space.getitem(space.newtuple(self.args_w), w_index) descr_getitem.unwrap_spec = ['self', ObjSpace, W_Root] def getdict(self): if self.w_dict is None: self.w_dict = self.space.newdict(instance=True) return self.w_dict def setdict(self, space, w_dict): if not space.is_true(space.isinstance( w_dict, space.w_dict )): raise OperationError( space.w_TypeError, space.wrap("setting exceptions's dictionary to a non-dict") ) self.w_dict = w_dict def descr_reduce(self, space): lst = [self.getclass(space), space.newtuple(self.args_w)] if self.w_dict is not None and space.is_true(self.w_dict): lst = lst + [self.w_dict] return space.newtuple(lst) descr_reduce.unwrap_spec = ['self', ObjSpace] def descr_setstate(self, space, w_dict): w_olddict = self.getdict() space.call_method(w_olddict, 'update', w_dict) descr_setstate.unwrap_spec = ['self', ObjSpace, W_Root] def _new(cls, basecls=None): if basecls is None: basecls = cls def descr_new_base_exception(space, w_subtype, __args__): exc = space.allocate_instance(cls, w_subtype) basecls.__init__(exc, space) return space.wrap(exc) descr_new_base_exception.unwrap_spec = [ObjSpace, W_Root, Arguments] descr_new_base_exception.func_name = 'descr_new_' + cls.__name__ return interp2app(descr_new_base_exception) W_BaseException.typedef = TypeDef( 'BaseException', __doc__ = W_BaseException.__doc__, __module__ = 'exceptions', __new__ = _new(W_BaseException), __init__ = interp2app(W_BaseException.descr_init), __str__ = interp2app(W_BaseException.descr_str), __repr__ = interp2app(W_BaseException.descr_repr), __dict__ = GetSetProperty(descr_get_dict, descr_set_dict, descr_del_dict, cls=W_BaseException), __getitem__ = interp2app(W_BaseException.descr_getitem), __reduce__ = interp2app(W_BaseException.descr_reduce), __setstate__ = interp2app(W_BaseException.descr_setstate), message = readwrite_attrproperty_w('w_message', W_BaseException), args = GetSetProperty(W_BaseException.descr_getargs, W_BaseException.descr_setargs), ) def _new_exception(name, base, docstring, **kwargs): # Create a subclass W_Exc of the class 'base'. Note that there is # hackery going on on the typedef of W_Exc: when we make further # app-level subclasses, they inherit at interp-level from 'realbase' # instead of W_Exc. This allows multiple inheritance to work (see # test_multiple_inheritance in test_exc.py). class W_Exc(base): __doc__ = docstring W_Exc.__name__ = 'W_' + name realbase = base.typedef.applevel_subclasses_base or base for k, v in kwargs.items(): kwargs[k] = interp2app(v.__get__(None, realbase)) W_Exc.typedef = TypeDef( name, base.typedef, __doc__ = W_Exc.__doc__, __module__ = 'exceptions', __new__ = _new(W_Exc, realbase), **kwargs ) W_Exc.typedef.applevel_subclasses_base = realbase return W_Exc W_Exception = _new_exception('Exception', W_BaseException, """Common base class for all non-exit exceptions.""") W_GeneratorExit = _new_exception('GeneratorExit', W_Exception, """Request that a generator exit.""") W_StandardError = _new_exception('StandardError', W_Exception, """Base class for all standard Python exceptions.""") W_ValueError = _new_exception('ValueError', W_StandardError, """Inappropriate argument value (of correct type).""") W_ImportError = _new_exception('ImportError', W_StandardError, """Import can't find module, or can't find name in module.""") W_RuntimeError = _new_exception('RuntimeError', W_StandardError, """Unspecified run-time error.""") W_UnicodeError = _new_exception('UnicodeError', W_ValueError, """Unicode related error.""") class W_UnicodeTranslateError(W_UnicodeError): """Unicode translation error.""" object = None start = None end = None reason = None def descr_init(self, space, w_object, w_start, w_end, w_reason): # typechecking space.realunicode_w(w_object) space.int_w(w_start) space.int_w(w_end) space.realstr_w(w_reason) # assign attributes self.w_object = w_object self.w_start = w_start self.w_end = w_end self.w_reason = w_reason W_BaseException.descr_init(self, space, [w_object, w_start, w_end, w_reason]) descr_init.unwrap_spec = ['self', ObjSpace, W_Root, W_Root, W_Root, W_Root] def descr_str(self, space): return space.appexec([space.wrap(self)], r"""(self): if self.end == self.start + 1: badchar = ord(self.object[self.start]) if badchar <= 0xff: return "can't translate character u'\\x%02x' in position %d: %s" % (badchar, self.start, self.reason) if badchar <= 0xffff: return "can't translate character u'\\u%04x' in position %d: %s"%(badchar, self.start, self.reason) return "can't translate character u'\\U%08x' in position %d: %s"%(badchar, self.start, self.reason) return "can't translate characters in position %d-%d: %s" % (self.start, self.end - 1, self.reason) """) descr_str.unwrap_spec = ['self', ObjSpace] W_UnicodeTranslateError.typedef = TypeDef( 'UnicodeTranslateError', W_UnicodeError.typedef, __doc__ = W_UnicodeTranslateError.__doc__, __module__ = 'exceptions', __new__ = _new(W_UnicodeTranslateError), __init__ = interp2app(W_UnicodeTranslateError.descr_init), __str__ = interp2app(W_UnicodeTranslateError.descr_str), object = readwrite_attrproperty_w('w_object', W_UnicodeTranslateError), start = readwrite_attrproperty_w('w_start', W_UnicodeTranslateError), end = readwrite_attrproperty_w('w_end', W_UnicodeTranslateError), reason = readwrite_attrproperty_w('w_reason', W_UnicodeTranslateError), ) W_LookupError = _new_exception('LookupError', W_StandardError, """Base class for lookup errors.""") def key_error_str(self, space): if len(self.args_w) == 0: return space.wrap('') elif len(self.args_w) == 1: return space.repr(self.args_w[0]) else: return space.str(space.newtuple(self.args_w)) key_error_str.unwrap_spec = ['self', ObjSpace] W_KeyError = _new_exception('KeyError', W_LookupError, """Mapping key not found.""", __str__ = key_error_str) W_StopIteration = _new_exception('StopIteration', W_Exception, """Signal the end from iterator.next().""") W_Warning = _new_exception('Warning', W_Exception, """Base class for warning categories.""") W_PendingDeprecationWarning = _new_exception('PendingDeprecationWarning', W_Warning, """Base class for warnings about features which will be deprecated in the future.""") class W_EnvironmentError(W_StandardError): """Base class for I/O related errors.""" def __init__(self, space): self.w_errno = space.w_None self.w_strerror = space.w_None self.w_filename = space.w_None W_BaseException.__init__(self, space) def descr_init(self, space, args_w): W_BaseException.descr_init(self, space, args_w) if 2 <= len(args_w) <= 3: self.w_errno = args_w[0] self.w_strerror = args_w[1] if len(args_w) == 3: self.w_filename = args_w[2] self.args_w = [args_w[0], args_w[1]] descr_init.unwrap_spec = ['self', ObjSpace, 'args_w'] # since we rebind args_w, we need special reduce, grump def descr_reduce(self, space): if not space.is_w(self.w_filename, space.w_None): lst = [self.getclass(space), space.newtuple( self.args_w + [self.w_filename])] else: lst = [self.getclass(space), space.newtuple(self.args_w)] if self.w_dict is not None and space.is_true(self.w_dict): lst = lst + [self.w_dict] return space.newtuple(lst) descr_reduce.unwrap_spec = ['self', ObjSpace] def descr_str(self, space): if (not space.is_w(self.w_errno, space.w_None) and not space.is_w(self.w_strerror, space.w_None)): if not space.is_w(self.w_filename, space.w_None): return space.wrap("[Errno %s] %s: %s" % ( space.str_w(space.str(self.w_errno)), space.str_w(self.w_strerror), space.str_w(space.repr(self.w_filename)))) return space.wrap("[Errno %s] %s" % (space.str_w(space.str(self.w_errno)), space.str_w(self.w_strerror))) return W_BaseException.descr_str(self, space) descr_str.unwrap_spec = ['self', ObjSpace] W_EnvironmentError.typedef = TypeDef( 'EnvironmentError', W_StandardError.typedef, __doc__ = W_EnvironmentError.__doc__, __module__ = 'exceptions', __new__ = _new(W_EnvironmentError), __reduce__ = interp2app(W_EnvironmentError.descr_reduce), __init__ = interp2app(W_EnvironmentError.descr_init), __str__ = interp2app(W_EnvironmentError.descr_str), errno = readwrite_attrproperty_w('w_errno', W_EnvironmentError), strerror = readwrite_attrproperty_w('w_strerror', W_EnvironmentError), filename = readwrite_attrproperty_w('w_filename', W_EnvironmentError), ) W_OSError = _new_exception('OSError', W_EnvironmentError, """OS system call failed.""") class W_WindowsError(W_OSError): """MS-Windows OS system call failed.""" def __init__(self, space): self.w_winerror = space.w_None W_OSError.__init__(self, space) def descr_init(self, space, args_w): # Set errno to the POSIX errno, and winerror to the Win32 # error code. W_OSError.descr_init(self, space, args_w) try: errno = space.int_w(self.w_errno) except OperationError: errno = self._default_errno else: errno = self._winerror_to_errno.get(errno, self._default_errno) self.w_winerror = self.w_errno self.w_errno = space.wrap(errno) descr_init.unwrap_spec = ['self', ObjSpace, 'args_w'] def descr_str(self, space): if (not space.is_w(self.w_winerror, space.w_None) and not space.is_w(self.w_strerror, space.w_None)): if not space.is_w(self.w_filename, space.w_None): return space.wrap("[Error %d] %s: %s" % ( space.int_w(self.w_winerror), space.str_w(self.w_strerror), space.str_w(self.w_filename))) return space.wrap("[Error %d] %s" % (space.int_w(self.w_winerror), space.str_w(self.w_strerror))) return W_BaseException.descr_str(self, space) descr_str.unwrap_spec = ['self', ObjSpace] if hasattr(rwin32, 'build_winerror_to_errno'): _winerror_to_errno, _default_errno = rwin32.build_winerror_to_errno() else: _winerror_to_errno, _default_errno = {}, 22 # EINVAL W_WindowsError.typedef = TypeDef( "WindowsError", W_OSError.typedef, __doc__ = W_WindowsError.__doc__, __module__ = 'exceptions', __new__ = _new(W_WindowsError), __init__ = interp2app(W_WindowsError.descr_init), __str__ = interp2app(W_WindowsError.descr_str), winerror = readwrite_attrproperty_w('w_winerror', W_WindowsError), ) W_DeprecationWarning = _new_exception('DeprecationWarning', W_Warning, """Base class for warnings about deprecated features.""") W_ArithmeticError = _new_exception('ArithmeticError', W_StandardError, """Base class for arithmetic errors.""") W_FloatingPointError = _new_exception('FloatingPointError', W_ArithmeticError, """Floating point operation failed.""") W_ReferenceError = _new_exception('ReferenceError', W_StandardError, """Weak ref proxy used after referent went away.""") W_NameError = _new_exception('NameError', W_StandardError, """Name not found globally.""") W_IOError = _new_exception('IOError', W_EnvironmentError, """I/O operation failed.""") class W_SyntaxError(W_StandardError): """Invalid syntax.""" def __init__(self, space): self.w_filename = space.w_None self.w_lineno = space.w_None self.w_offset = space.w_None self.w_text = space.w_None self.w_msg = space.wrap('') self.w_print_file_and_line = space.w_None # what's that? W_BaseException.__init__(self, space) def descr_init(self, space, args_w): # that's not a self.w_message!!! if len(args_w) > 0: self.w_msg = args_w[0] if len(args_w) == 2: values_w = space.fixedview(args_w[1], 4) self.w_filename = values_w[0] self.w_lineno = values_w[1] self.w_offset = values_w[2] self.w_text = values_w[3] W_BaseException.descr_init(self, space, args_w) descr_init.unwrap_spec = ['self', ObjSpace, 'args_w'] def descr_str(self, space): return space.appexec([self], """(self): if type(self.msg) is not str: return str(self.msg) buffer = self.msg have_filename = type(self.filename) is str have_lineno = type(self.lineno) is int if have_filename: import os fname = os.path.basename(self.filename or "???") if have_lineno: buffer = "%s (%s, line %ld)" % (self.msg, fname, self.lineno) else: buffer ="%s (%s)" % (self.msg, fname) elif have_lineno: buffer = "%s (line %ld)" % (self.msg, self.lineno) return buffer """) descr_str.unwrap_spec = ['self', ObjSpace] W_SyntaxError.typedef = TypeDef( 'SyntaxError', W_StandardError.typedef, __new__ = _new(W_SyntaxError), __init__ = interp2app(W_SyntaxError.descr_init), __str__ = interp2app(W_SyntaxError.descr_str), __doc__ = W_SyntaxError.__doc__, __module__ = 'exceptions', msg = readwrite_attrproperty_w('w_msg', W_SyntaxError), filename = readwrite_attrproperty_w('w_filename', W_SyntaxError), lineno = readwrite_attrproperty_w('w_lineno', W_SyntaxError), offset = readwrite_attrproperty_w('w_offset', W_SyntaxError), text = readwrite_attrproperty_w('w_text', W_SyntaxError), print_file_and_line = readwrite_attrproperty_w('w_print_file_and_line', W_SyntaxError), ) W_FutureWarning = _new_exception('FutureWarning', W_Warning, """Base class for warnings about constructs that will change semantically in the future.""") class W_SystemExit(W_BaseException): """Request to exit from the interpreter.""" def __init__(self, space): self.w_code = space.w_None W_BaseException.__init__(self, space) def descr_init(self, space, args_w): if len(args_w) == 1: self.w_code = args_w[0] elif len(args_w) > 1: self.w_code = space.newtuple(args_w) W_BaseException.descr_init(self, space, args_w) descr_init.unwrap_spec = ['self', ObjSpace, 'args_w'] W_SystemExit.typedef = TypeDef( 'SystemExit', W_BaseException.typedef, __new__ = _new(W_SystemExit), __init__ = interp2app(W_SystemExit.descr_init), __doc__ = W_SystemExit.__doc__, __module__ = 'exceptions', code = readwrite_attrproperty_w('w_code', W_SystemExit) ) W_EOFError = _new_exception('EOFError', W_StandardError, """Read beyond end of file.""") W_IndentationError = _new_exception('IndentationError', W_SyntaxError, """Improper indentation.""") W_TabError = _new_exception('TabError', W_IndentationError, """Improper mixture of spaces and tabs.""") W_ZeroDivisionError = _new_exception('ZeroDivisionError', W_ArithmeticError, """Second argument to a division or modulo operation was zero.""") W_SystemError = _new_exception('SystemError', W_StandardError, """Internal error in the Python interpreter. Please report this to the Python maintainer, along with the traceback, the Python version, and the hardware/OS platform and version.""") W_AssertionError = _new_exception('AssertionError', W_StandardError, """Assertion failed.""") class W_UnicodeDecodeError(W_UnicodeError): """Unicode decoding error.""" w_encoding = None w_object = None w_start = None w_end = None w_reason = None def descr_init(self, space, w_encoding, w_object, w_start, w_end, w_reason): # typechecking space.realstr_w(w_encoding) space.realstr_w(w_object) space.int_w(w_start) space.int_w(w_end) space.realstr_w(w_reason) # assign attributes self.w_encoding = w_encoding self.w_object = w_object self.w_start = w_start self.w_end = w_end self.w_reason = w_reason W_BaseException.descr_init(self, space, [w_encoding, w_object, w_start, w_end, w_reason]) descr_init.unwrap_spec = ['self', ObjSpace, W_Root, W_Root, W_Root, W_Root, W_Root] def descr_str(self, space): return space.appexec([self], """(self): if self.end == self.start + 1: return "%r codec can't decode byte 0x%02x in position %d: %s"%( self.encoding, ord(self.object[self.start]), self.start, self.reason) return "%r codec can't decode bytes in position %d-%d: %s" % ( self.encoding, self.start, self.end - 1, self.reason) """) descr_str.unwrap_spec = ['self', ObjSpace] W_UnicodeDecodeError.typedef = TypeDef( 'UnicodeDecodeError', W_UnicodeError.typedef, __doc__ = W_UnicodeDecodeError.__doc__, __module__ = 'exceptions', __new__ = _new(W_UnicodeDecodeError), __init__ = interp2app(W_UnicodeDecodeError.descr_init), __str__ = interp2app(W_UnicodeDecodeError.descr_str), encoding = readwrite_attrproperty_w('w_encoding', W_UnicodeDecodeError), object = readwrite_attrproperty_w('w_object', W_UnicodeDecodeError), start = readwrite_attrproperty_w('w_start', W_UnicodeDecodeError), end = readwrite_attrproperty_w('w_end', W_UnicodeDecodeError), reason = readwrite_attrproperty_w('w_reason', W_UnicodeDecodeError), ) W_TypeError = _new_exception('TypeError', W_StandardError, """Inappropriate argument type.""") W_IndexError = _new_exception('IndexError', W_LookupError, """Sequence index out of range.""") W_RuntimeWarning = _new_exception('RuntimeWarning', W_Warning, """Base class for warnings about dubious runtime behavior.""") W_KeyboardInterrupt = _new_exception('KeyboardInterrupt', W_BaseException, """Program interrupted by user.""") W_UserWarning = _new_exception('UserWarning', W_Warning, """Base class for warnings generated by user code.""") W_SyntaxWarning = _new_exception('SyntaxWarning', W_Warning, """Base class for warnings about dubious syntax.""") W_UnicodeWarning = _new_exception('UnicodeWarning', W_Warning, """Base class for warnings about Unicode related problems, mostly related to conversion problems.""") W_ImportWarning = _new_exception('ImportWarning', W_Warning, """Base class for warnings about probable mistakes in module imports""") W_MemoryError = _new_exception('MemoryError', W_StandardError, """Out of memory.""") W_UnboundLocalError = _new_exception('UnboundLocalError', W_NameError, """Local name referenced but not bound to a value.""") W_NotImplementedError = _new_exception('NotImplementedError', W_RuntimeError, """Method or function hasn't been implemented yet.""") W_AttributeError = _new_exception('AttributeError', W_StandardError, """Attribute not found.""") W_OverflowError = _new_exception('OverflowError', W_ArithmeticError, """Result too large to be represented.""") class W_UnicodeEncodeError(W_UnicodeError): """Unicode encoding error.""" w_encoding = None w_object = None w_start = None w_end = None w_reason = None def descr_init(self, space, w_encoding, w_object, w_start, w_end, w_reason): # typechecking space.realstr_w(w_encoding) space.realunicode_w(w_object) space.int_w(w_start) space.int_w(w_end) space.realstr_w(w_reason) # assign attributes self.w_encoding = w_encoding self.w_object = w_object self.w_start = w_start self.w_end = w_end self.w_reason = w_reason W_BaseException.descr_init(self, space, [w_encoding, w_object, w_start, w_end, w_reason]) descr_init.unwrap_spec = ['self', ObjSpace, W_Root, W_Root, W_Root, W_Root, W_Root] def descr_str(self, space): return space.appexec([self], r"""(self): if self.end == self.start + 1: badchar = ord(self.object[self.start]) if badchar <= 0xff: return "%r codec can't encode character u'\\x%02x' in position %d: %s"%( self.encoding, badchar, self.start, self.reason) if badchar <= 0xffff: return "%r codec can't encode character u'\\u%04x' in position %d: %s"%( self.encoding, badchar, self.start, self.reason) return "%r codec can't encode character u'\\U%08x' in position %d: %s"%( self.encoding, badchar, self.start, self.reason) return "%r codec can't encode characters in position %d-%d: %s" % ( self.encoding, self.start, self.end - 1, self.reason) """) descr_str.unwrap_spec = ['self', ObjSpace] W_UnicodeEncodeError.typedef = TypeDef( 'UnicodeEncodeError', W_UnicodeError.typedef, __doc__ = W_UnicodeEncodeError.__doc__, __module__ = 'exceptions', __new__ = _new(W_UnicodeEncodeError), __init__ = interp2app(W_UnicodeEncodeError.descr_init), __str__ = interp2app(W_UnicodeEncodeError.descr_str), encoding = readwrite_attrproperty_w('w_encoding', W_UnicodeEncodeError), object = readwrite_attrproperty_w('w_object', W_UnicodeEncodeError), start = readwrite_attrproperty_w('w_start', W_UnicodeEncodeError), end = readwrite_attrproperty_w('w_end', W_UnicodeEncodeError), reason = readwrite_attrproperty_w('w_reason', W_UnicodeEncodeError), )