Python Error System Exit
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a try statement with an except clause that mentions a particular class, that clause type error python also handles any exception classes derived from that class (but
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not exception classes from which it is derived). Two exception classes that are not related via
Python Custom Exception
subclassing are 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
Python Exception Message
where mentioned, they 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 python valueerror example 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. 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 han
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 python exception class methods posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss python 3 exceptions 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 python errno takes a minute: Sign up Is there a way to prevent a SystemExit exception raised from sys.exit() from being caught? up vote 33 down vote favorite 7 The docs say that calling sys.exit() raises a SystemExit exception which can be caught https://docs.python.org/3/library/exceptions.html in outer levels. I have a situation in which I want to definitively and unquestionably exit from inside a test case, however the unittest module catches SystemExit and prevents the exit. This is normally great, but the specific situation I am trying to handle is one where our test framework has detected that it is configured to point to a non-test database. In this case I want to exit and prevent any further tests from being run. Of course since unittest http://stackoverflow.com/questions/173278/is-there-a-way-to-prevent-a-systemexit-exception-raised-from-sys-exit-from-bei traps the SystemExit and continues happily on it's way, it is thwarting me. The only option I have thought of so far is using ctypes or something similar to call exit(3) directly but this seems like a pretty fugly hack for something that should be really simple. python exception exit systemexit share|improve this question asked Oct 6 '08 at 5:40 John 7,09164251 This is also relevant when trying to exit a program from an embedded IPython shell. –quazgar Oct 10 at 12:17 add a comment| 2 Answers 2 active oldest votes up vote 45 down vote accepted You can call os._exit() to directly exit, without throwing an exception: import os os._exit(1) This bypasses all of the python shutdown logic, such as the atexit module, and will not run through the exception handling logic that you're trying to avoid in this situation. The argument is the exit code that will be returned by the process. share|improve this answer edited Jul 31 '15 at 23:21 Anthony Hilyard 856420 answered Oct 6 '08 at 6:24 Jerub 25.4k105587 add a comment| up vote 29 down vote As Jerub said, os._exit(1) is your answer. But, considering it bypasses all cleanup procedures, including finally: blocks, closing files, etc, and should really be avoided at all costs, may I present a "safer-ish" way of using it? If you problem is SystemExit being caught at outer levels (ie, unittest), then be the outer level yourself! Wrap
here for a quick overview of the site Help Center Detailed answers to http://stackoverflow.com/questions/13612434/why-are-the-methods-sys-exit-exit-raise-systemexit-not-working any questions you might have Meta Discuss the workings and http://stackoverflow.com/questions/10166686/how-do-i-exit-program-in-try-except 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 python exception 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 Why are the methods sys.exit(), exit(), raise SystemExit not working? up vote 5 down vote favorite I need an alternative to kill the python script while inside a python error system thread function. My intention is killing the server when the client enters a 0... Is this not working because the threads haven't been terminated? Here is my code: socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM); print 'Socket created' try: socket.bind((HOST, PORT)) except socket.error, message: print 'Bind statement failed. ERROR: ' + str(message[0]) + ' Message: ' + message[1] sys.exit() print 'Socket Binding Successful' socket.listen(10) print 'Socket is currently listening' def clientThread(connection): while 1: data = connect.recv(1024) try: quit = int(data) except: quit = 3 if quit == 0: print 'Closing the connection and socket...' connect.close() socket.close() sys.exit(); //Alternative needed here... break reply = 'Ok....' + data if not data: break connect.sendall(reply) while 1: #forever loop connect, address = socket.accept() print 'Just connected with ' + address[0] + ' : ' + str(address[1]) start_new_thread(clientThread, (connect,)) socket.close() python multithreading sockets exit sys share|improve this question asked Nov 28 '12 at 18:59 CS Gamer 145110 add a comm
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 how do I exit program in try except up vote 10 down vote favorite i have this try except code: document = raw_input ('Your document name is ') try: with open(document, 'r') as a: for element in a: print element except: print document, 'does not exist' my question is, how do i exit the program after I print filename does not exist? break and pass don't work obviously. and i don't want to have any crashing error, so sys.exit is not an option. please kindly ignore the try part because it's just a dummy :) thanks! python share|improve this question asked Apr 15 '12 at 22:25 rudster 1912314 add a comment| 4 Answers 4 active oldest votes up vote 14 down vote Use the sys.exit: import sys try: # do something except Exception, e: print >> sys.stderr, "does not exist" print >> sys.stderr, "Exception: %s" % str(e) sys.exit(1) A good practice is to print the Exception that occured so you can debug afterwards. You can also print the stacktrace with the traceback module. Note that the int you return in sys.exit will be the return code of your program. To see what exit code your program returned (which will give you information about what happens and can be automated), you can do: echo $? share|improve this answer edited Apr 15 '12 at 22:39 answered Apr 15 '12 at 22:27 Charles Menguy 20.3k135893 add a comment| up vote 5 down vote You can also put your code in a function and issue