Python Error Not Found
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a try statement with an except clause that mentions a particular python filenotfounderror class, that clause also handles any exception classes derived from type error python that class (but not exception classes from which it is derived). Two exception classes that python custom exception are not related via subclassing are never equivalent, even if they have the same name. The built-in exceptions listed below can be generated by the python exception message 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 of several items of information (e.g., an error code and a string explaining the code). The associated value is usually passed as arguments
Python Valueerror Example
to the exception class's constructor. 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. 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
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Python Exception Class Methods
company Business Learn more about hiring developers or posting ads with us Stack Overflow python 3 exceptions Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 6.2 python errno million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Python's “open()” throws different errors for “file not found” - how to handle both exceptions? up vote 29 down https://docs.python.org/3/library/exceptions.html vote favorite 6 I have a script where a user is prompted to type a filename (of a file that is to be opened), and if the file doesn't exist in the current directory, the user is prompted again. Here is the short version: file = input("Type filename: ") ... try: fileContent = open(filename, "r") ... except FileNotFoundError: ... When I tested my script on my MacOS X in Python 3.3x it worked http://stackoverflow.com/questions/15032108/pythons-open-throws-different-errors-for-file-not-found-how-to-handle-b perfectly fine when I type the wrong filename on purpose (it executes the suite under "expect"). However, when I wanted to run my code on a Windows computer in Python 3.2x, I get an error that says that "FileNotFoundError" is not defined. So, Python 3.2 on Windows thinks "FileNotFoundError" is a variable and the programs quits with an error. I figured out that Python 3.2 on Windows throws an "IOError" if the input filename is not valid. I tested it on my Linux machine in Python 2.7, and it's also an IOError. My problem is now, that the code with except "FileNotFoundError": won't run on Windows's Python 3.2, but if I change it to except "IOError": it won't work on my Mac anymore. How could I work around it? The only way I can think of is to use just except, which I usually don't want. python python-3.x filenotfoundexception ioerror share|improve this question edited Feb 22 '13 at 19:57 asked Feb 22 '13 at 19:48 user2015601 6 This isn't due to Mac/Windows, it's the version of Python. I would investigate 3.2/3.3 on OS X as well (and 3.3 on Windows), consult the change logs, and then revise the question/title as appropriate. –user166390 Feb 22 '13 at 19:53 add a comment| 4 Answers 4 active oldest votes
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 http://stackoverflow.com/questions/4207790/what-exception-is-thrown-when-key-is-not-found-in-python-dictionary 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 What exception is thrown when key is not found in Python dictionary? up vote 10 down vote favorite 1 If I have: map = { 'stack':'overflow' } try: map['experts-exchange'] python exception except: <--- What is the Exception type that's thrown here? print( 'is not free' ) Couldn't find it on the web. =( python exception dictionary share|improve this question asked Nov 17 '10 at 18:27 sivabudh 12.1k35118189 3 Where did you look? The page at docs.python.org/library/stdtypes.html says "d[key] -- Return the item of d with key key. Raises a KeyError if key is not in the map." –bgporter Nov 17 '10 at 18:31 2 You should use python error not the interactive console to view results like this. –jsbueno Nov 17 '10 at 18:45 4 It's very disappointing that someone would ask a question like this on SO (or anywhere else) instead of taking the five seconds it would take to simply try referencing a nonexistent key in a dictionary and seeing what Python does. –Robert Rossney Nov 17 '10 at 19:18 5 -1 for asking something because you're too lazy to keep looking or try it yourself. -1000 for using Bing –Falmarri Nov 17 '10 at 20:47 1 I think the question isn't too bad because when someone searches for it, it will show up on the search engine instead of having to search for it, right? –sivabudh Nov 17 '10 at 21:15 | show 2 more comments 4 Answers 4 active oldest votes up vote 19 down vote accepted KeyError if you do it on the console without the try block will tell it to you >>> a = {} >>> a['invalid'] Traceback (most recent call last): File "