Python Does Not Exist Error
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Django Catch Doesnotexist
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Django Doesnotexist Matching Query Does Not Exist
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 Django DoesNotExist up vote 24 down vote favorite django exception handling 4 I am having issues on trying to figure "DoesNotExist Errors", I have tried to find the right way for manage the no answer results, however I continue having issues on "DoesNotExist" or "Object hast not Attribute DoestNotExists" from django.http import HttpResponse from django.contrib.sites.models import Site from django.utils import simplejson from vehicles.models import * from gpstracking.models import * def request_statuses(request): data = [] vehicles = Vehicle.objects.filter() Vehicle.vehicledevice_ for vehicle in vehicles: try: vehicledevice = vehicle.vehicledevice_set.get(is_joined__exact = True) imei = vehicledevice.device.imei try: lastposition = vehicledevice.device.devicetrack_set.latest('date_time_process') altitude = lastposition.altitude latitude = lastposition.latitude longitude = lastposition.longitude date_time_process = lastposition.date_time_process.strftime("%Y-%m-%d %H:%M:%S"), date_time_created = lastposition.created.strftime("%Y-%m-%d %H:%M:%S") except Vehicle.vehicledevice.device.DoesNotExist: lastposition = None altitude = None latitude = None longitude = None date_time_process = None date_time_created = None except Vehicle.DoesNotExist: vehicledevice = None imei = '' item = [
This module never needs to be imported explicitly: the exceptions are provided in the built-in namespace as well as the exceptions module.
Django Raise Exception
For class exceptions, in a try statement with an class="pre">except Working with File Objects 6.2.1. Reading Files 6.2.2. Closing Files 6.2.3. Handling I/O Errors 6.2.4. Writing to Files 6.3. Iterating with for Loops 6.4. Using sys.modules 6.5. Working with Directories 6.6. Putting It All Together 6.7. Summary In this chapter, you will http://www.diveintopython.net/file_handling/ dive into exceptions, file objects, for loops, and the os and sys modules. If you've https://www.tutorialspoint.com/python/standard_exceptions.htm used exceptions in another programming language, you can skim the first section to get a sense of Python's syntax. Be sure to tune in again for file handling. 6.1.Handling Exceptions 6.1.1. Using Exceptions For Other Purposes Like many other programming languages, Python has exception handling via try...except blocks. Python uses try...except to handle exceptions and raise to generate them. Java and does not C++ use try...catch to handle exceptions, and throw to generate them. Exceptions are everywhere in Python. Virtually every module in the standard Python library uses them, and Python itself will raise them in a lot of different circumstances. You've already seen them repeatedly throughout this book. Accessing a non-existent dictionary key will raise a KeyError exception. Searching a list for a non-existent value will raise a ValueError exception. Calling a non-existent method will raise an AttributeError exception. does not exist Referencing a non-existent variable will raise a NameError exception. Mixing datatypes without coercion will raise a TypeError exception. In each of these cases, you were simply playing around in the Python IDE: an error occurred, the exception was printed (depending on your IDE, perhaps in an intentionally jarring shade of red), and that was that. This is called an unhandled exception. When the exception was raised, there was no code to explicitly notice it and deal with it, so it bubbled its way back to the default behavior built in to Python, which is to spit out some debugging information and give up. In the IDE, that's no big deal, but if that happened while your actual Python program was running, the entire program would come to a screeching halt. An exception doesn't need result in a complete program crash, though. Exceptions, when raised, can be handled. Sometimes an exception is really because you have a bug in your code (like accessing a variable that doesn't exist), but many times, an exception is something you can anticipate. If you're opening a file, it might not exist. If you're connecting to a database, it might be unavailable, or you might not have the correct security credentials to access it. If you know a line of code may raise an exception, you should handle the exception using a try Python - Basic Syntax Python - Variable Types Python - Basic Operators Python - Decision Making Python - Loops Python - Numbers Python - Strings Python - Lists Python - Tuples Python - Dictionary Python - Date & Time Python - Functions Python - Modules Python - Files I/O Python - Exceptions Python Advanced Tutorial Python - Classes/Objects Python - Reg Expressions Python - CGI Programming Python - Database Access Python - Networking Python - Sending Email Python - Multithreading Python - XML Processing Python - GUI Programming Python - Further Extensions Python Useful Resources Python - Questions and Answers Python - Quick Guide Python - Tools/Utilities Python - Useful Resources Python - Discussion Selected Reading Developer's Best Practices Questions and Answers Effective Resume Writing HR Interview Questions Computer Glossary Who is Who Python Standard Exceptions Advertisements Previous Page Next Page Here is a list all the standard Exceptions available in Python: EXCEPTION NAMEDESCRIPTION ExceptionBase class for all exceptions StopIterationRaised when the next() method of an iterator does not point to any object. SystemExitRaised by the sys.exit() function. StandardErrorBase class for all built-in exceptions except StopIteration and SystemExit. ArithmeticErrorBase class for all errors that occur for numeric calculation. OverflowErrorRaised when a calculation exceeds maximum limit for a numeric type. FloatingPointErrorRaised when a floating point calculation fails. ZeroDivisonErrorRaised when division or modulo by zero takes place for all numeric types. AssertionErrorRaised in case of failure of the Assert statement. AttributeErrorRaised in case of failure of attribute reference or assignment. EOFErrorRaised when there is no input from either the raw_input() or input() function and the end of file is reached. ImportErrorRaised when an import statement fails. KeyboardInterruptRaised when the user interrupts program execution, usually by pressing Ctrl+c. LookupErrorBase class for all lookup errors. IndexErrorRaised when an index is not found in a sequence. KeyErrorRaised when the specified key is not found in the dictionary. NameErrorRaisePython Custom Exception