Python Exception Error List
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Python Exception Message
KeyboardInterrupt MemoryError NameError NotImplementedError OSError OverflowError ReferenceError RuntimeError StopIteration SyntaxError SystemError python custom exception SystemExit TypeError UnboundLocalError UnicodeError ValueError ZeroDivisionError Warning Categories Navigation Table of Contents Previous: Built-in Objects Next: python exception stack trace String Services This Page Show Source Examples The output from all the example programs from PyMOTW has been generated with Python 2.7.8, unless otherwise noted. Some of
Python Raise Valueerror
the features described here may not be available in earlier versions of Python. If you are looking for examples that work under Python 3, please refer to the PyMOTW-3 section of the site. Navigation index modules | next | previous | PyMOTW » Built-in Objects » exceptions - Built-in error classes¶ Purpose:The exceptions module
Python Catch Multiple Exceptions
defines the built-in errors used throughout the standard library and by the interpreter. Available In:1.5 and later Description¶ In the past, Python has supported simple string messages as exceptions as well as classes. Since 1.5, all of the standard library modules use classes for exceptions. Starting with Python 2.5, string exceptions result in a DeprecationWarning, and support for string exceptions will be removed in the future. Base Classes¶ The exception classes are defined in a hierarchy, described in the standard library documentation. In addition to the obvious organizational benefits, exception inheritance is useful because related exceptions can be caught by catching their base class. In most cases, these base classes are not intended to be raised directly. BaseException¶ Base class for all exceptions. Implements logic for creating a string representation of the exception using str() from the arguments passed to the constructor. Exception¶ Base class for exceptions that do not result in quitting the running application. All user-defined exceptions shoul
This module never needs to be imported explicitly: the exceptions are provided in the built-in namespace as well as the python print exception exceptions module. For class exceptions, in a try statement
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with an except clause that mentions a particular class, that clause also handles any exception classes python exception class methods derived from that class (but not exception classes from which it is derived). Two exception classes that are not related via subclassing are never equivalent, even if https://pymotw.com/2/exceptions/ they have the same name. The built-in exceptions listed below can be generated by the interpreter or built-in functions. Except where mentioned, they have an "associated value" indicating the detailed cause of the error. This may be a string or a tuple containing several items of information (e.g., an error code and a string https://docs.python.org/2/library/exceptions.html explaining the code). The associated value is the second argument to the raise statement. If the exception class is derived from the standard root class BaseException, the associated value is present as the exception instance's args attribute. User code can raise built-in exceptions. This can be used to test an exception handler or to report an error condition "just like" the situation in which the interpreter raises the same exception; but beware that there is nothing to prevent user code from raising an inappropriate error. The built-in exception classes can be subclassed to define new exceptions; programmers are encouraged to derive new exceptions from the Exception class or one of its subclasses, and not from BaseException. More information on defining exceptions is available in the Python Tutorial under User-defined Exceptions. The following exceptions are only used as base classes for other exceptions. exception BaseException¶ The base class for all built-in exceptions. It is not meant to b
a try statement with an except clause that mentions a particular class, that clause also https://docs.python.org/3/library/exceptions.html handles any exception classes derived from that class (but not exception classes from which it is derived). Two exception classes that are not related via subclassing are http://stackoverflow.com/questions/6180185/custom-python-exceptions-with-error-codes-and-error-messages never equivalent, even if they have the same name. The built-in exceptions listed below can be generated by the interpreter or built-in functions. Except where mentioned, they python exception have an "associated value" indicating the detailed cause of the error. This may be a string or a tuple of several items of information (e.g., an error code and a string explaining the code). The associated value is usually passed as arguments to the exception class's constructor. User code can raise built-in exceptions. This python exception error can be used to test an exception handler or to report an error condition "just like" the situation in which the interpreter raises the same exception; but beware that there is nothing to prevent user code from raising an inappropriate error. The built-in exception classes can be subclassed to define new exceptions; programmers are encouraged to derive new exceptions from the Exception class or one of its subclasses, and not from BaseException. More information on defining exceptions is available in the Python Tutorial under User-defined Exceptions. When raising (or re-raising) an exception in an except or finally clause __context__ is automatically set to the last exception caught; if the new exception is not handled the traceback that is eventually displayed will include the originating exception(s) and the final exception. 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 supp
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 6.2 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Custom Python Exceptions with Error Codes and Error Messages up vote 22 down vote favorite 11 class AppError(Exception): pass class MissingInputError(AppError): pass class ValidationError(AppError): pass ... def validate(self): """ Validate Input and save it """ params = self.__params if 'key' in params: self.__validateKey(escape(params['key'][0])) else: raise MissingInputError if 'svc' in params: self.__validateService(escape(params['svc'][0])) else: raise MissingInputError if 'dt' in params: self.__validateDate(escape(params['dt'][0])) else: raise MissingInputError def __validateMulti(self, m): """ Validate Multiple Days Request""" if m not in Input.__validDays: raise ValidationError self.__dCast = int(m) validate() and __validateMulti() are methods of a class that validates and store the passed input parameters. As is evident in the code, I raise some custom exceptions when some input parameter is missing or some validation fails. I'd like to define some custom error codes and error messages specific to my app like, Error 1100: "Key parameter not found. Please verify your input." Error 1101: "Date parameter not found. Please verify your input" ... Error 2100: "Multiple Day parameter is not valid. Accepted values are 2, 5 and 7." and report the same to the user. How do I define these error codes and error messages in the custom exceptions? How do I raise / trap exception in a way that I know what error code / message to display? (P.S: This is for Python 2.4.3). Bastien Léonard mentions in this SO comment that you don't need to always define a new __init__ or __str__; by default, arguments will be placed in self.args and they will be printed by __str__. Thus, the solution I prefer: class AppError(Exception): pass class MissingInputError(AppError): # define the error codes & messages here em = {1101: "Some error here. Please verify.", \ 1102: "Another here. Please verify.", \ 1103: "One more here. Please verify.", \ 1104: "That was idiotic. Please verify."} Usage: try: # do something here that calls # raise MissingInputError(1101) except MissingInputError, e print "%d: %s" % (e.args[0], e.em[e.args[0]]) pytho