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Python Built In Error Classes


It is a subclass of ValueError. Changed in version 2.5: Changed to inherit from BaseException. KeyError Raised when a key is not found in a dictionary. exception IndentationError¶ Base class for syntax errors related to incorrect indentation. Check This Out

If you use the deprecated message attribute, assigning it yourself will avoid a DeprecationWarning: class MyAppValueError(ValueError): '''Raise when a specific subset of values in context of app is wrong''' def __init__(self, Corresponds to errno ENOTDIR. The os._exit() function can be used if it is absolutely positively necessary to exit immediately (for example, in the child process after a call to os.fork()). def throws_global_name_error(): print unknown_global_name def throws_unbound_local(): local_val = local_val + 1 print local_val try: throws_global_name_error() except NameError, err: print 'Global name error:', err try: throws_unbound_local() except UnboundLocalError, err: print 'Local name https://docs.python.org/2/library/exceptions.html

Python Typeerror

import math import fpectl print 'Control off:', math.exp(1000) fpectl.turnon_sigfpe() print 'Control on:', math.exp(1000) GeneratorExit¶ Raised inside a generator the generator's close() method is called. exception DeprecationWarning¶ Base class for warnings about deprecated features. The associated value is a string giving details about the type mismatch.

  1. exception FileExistsError¶ Raised when trying to create a file or directory which already exists.
  2. TypeError is a kind of Exception.
  3. exception ArithmeticError¶ The base class for those built-in exceptions that are raised for various arithmetic errors: OverflowError, ZeroDivisionError, FloatingPointError.
  4. The builtin ones are very nice, and your cooperative inheritance ensures that you use it.
  5. Also, this exception derives directly from BaseException and not Exception, since it is not technically an error.
  6. The traceback describes the process flow.
  7. exception GeneratorExit¶ Raised when a generator or coroutine is closed; see generator.close() and coroutine.close().
  8. SystemErrors probably indicate a bug in the interpreter and should be reported to the maintainer.
  9. UnboundLocalError Raised when a reference is made to a local variable in a function or method, but no value has been bound to that variable.
  10. This attribute is available when using the buffered I/O classes from the io module. exception ChildProcessError¶ Raised when an operation on a child process failed.

exception OverflowError¶ Raised when the result of an arithmetic operation is too large to be represented. SyntaxError Raised by parser when syntax error is encountered. l = [1,2,3] ... Python Exception Message Exception hierarchy¶ The class hierarchy for built-in exceptions is: BaseException +-- SystemExit +-- KeyboardInterrupt +-- GeneratorExit +-- Exception +-- StopIteration +-- StandardError | +-- BufferError | +-- ArithmeticError | | +--

It is a subclass of UnicodeError. Python Valueerror Example Some of the common built-in exceptions in Python programming along with the error that cause then are tabulated below. A call to sys.exit() is translated into an exception so that clean-up handlers (finally clauses of try statements) can be executed, and so that a debugger can execute more info here Navigation index modules | next | previous | Python » 3.3.6 Documentation » The Python Standard Library » © Copyright 1990-2014, Python Software Foundation.

The code that handles this exception will, ofc, import it –Alvaro Feb 3 '15 at 19:56 @Alvaro I didn't say it was wrong, it just has the downside of Python Exception Class Methods Exception hierarchy¶ The class hierarchy for built-in exceptions is: BaseException +-- SystemExit +-- KeyboardInterrupt +-- GeneratorExit +-- Exception +-- StopIteration +-- ArithmeticError | +-- FloatingPointError | +-- OverflowError | +-- ZeroDivisionError PyMOTW Home Blog The Book About Site Index If you find this information useful, consider picking up a copy of my book, The Python Standard Library By Example. This can be raised directly by codecs.lookup().

Python Valueerror Example

SyntaxErrorRaised when there is an error in Python syntax. You have successfully subscribed to Python newsletter. Python Typeerror Base classes¶ The following exceptions are used mostly as base classes for other exceptions. Python Custom Exception strerror¶ The corresponding error message, as provided by the operating system.

This is because a MyIndexError IS an IndexError. http://vealcine.com/python-exception/python-value-error.php That's not a whole lot of extra code you need per class. ;) share|improve this answer answered Aug 23 '09 at 21:58 Lennart Regebro 75k17134202 add a comment| Your Answer When raising a new exception (rather than using a bare raise to re-raise the exception currently being handled), the implicit exception context can be supplemented with an explicit cause by exception IOError¶ Raised when an I/O operation (such as a print statement, the built-in open() function or a method of a file object) fails for an I/O-related reason, e.g., Python Filenotfounderror

except statement has an optional else clause. If we call the above script with a non-existing file, we get the message: I/O error(2): No such file or directory And if the file integers.txt is not readable, e.g. If from X import Y is used and Y cannot be found inside the module X, an ImportError is raised. http://vealcine.com/python-exception/python-error-classes.php SystemError ............

It even has line numbers. Python Errno For more information on weak references, see the weakref module. Instances of this class have attributes filename, lineno, offset and text for easier access to the details. str() of the exception instance returns only the message.

For example, err.object[err.start:err.end] gives the particular invalid input that the codec failed on.

Hot Network Questions Set literal gives different result from set function call Should two DFAs be complete before making an intersection of them? share|improve this answer edited Jun 13 '14 at 23:39 Jim Ferrans 17.7k74167 answered Apr 22 '12 at 18:18 frnknstn 2,3321912 4 It looks like you shouldn't inherit from base exception. a "finally" clause is always executed regardless if an exception occurred in a try block or not. Python Attributeerror Object Has No Attribute Created using Sphinx 1.3.3.

User code can raise built-in exceptions. Non payment on (Phone) Handset Lease Half the pentagon! This seems like a pretty reasonable reaction. http://vealcine.com/python-exception/python-default-error-classes.php Every time you raise an OhMyGoodnessExc, the same thing happens.

This can be raised directly by codecs.lookup(). 5.2. This is a subclass of IndentationError. In any case, you only need the __init__ or __str__ if you do something different from what Exception itself does. exception ImportWarning¶ Base class for warnings about probable mistakes in module imports.


current community chat Stack Overflow Meta Stack Overflow your communities Sign up or log in to customize your list. See also PEP 3151 - Reworking the OS and IO exception hierarchy 5.3. Corresponds to errno ECONNABORTED. It is a subclass of UnicodeError.

That's an interesting constraint that future users may not appreciate. class NastyError(ExceptionTemplate): pass and if you don't like that default tuple-like representation, just add __str__ method to the ExceptionTemplate class, like: # ... exception ConnectionAbortedError¶ A subclass of ConnectionError, raised when a connection attempt is aborted by the peer. asked 7 years ago viewed 235699 times active 1 month ago Blog Stack Overflow Podcast #92 - The Guerilla Guide to Interviewing Visit Chat Linked 1 How to write a custom

Base classes¶ The following exceptions are used mostly as base classes for other exceptions. start¶ The first index of invalid data in object. assert i >= 1 ... Note that because of the underlying memory management architecture (C's malloc() function), the interpreter may not always be able to completely recover from this situation; it nevertheless raises an exception

In user defined base classes, abstract methods should raise this exception when they require derived classes to override the method. That seems like a lot of typing, is it necessary? You would need to do something like this: try: raise MyException({"message":"My hovercraft is full of animals", "animal":"eels"}) except MyException as e: details = e.args[0] print(details["animal"]) It is still possible to pass converting KeyError to AttributeError, while leaving the old exception available in __context__ for introspection when debugging.

Please try again ... The errno and strerror attributes are also None when the instance was created with other than 2 or 3 arguments.