Catch multiple exceptions in one line except block

Question

I know that I can do   try        do something that may fail except        do this if ANYTHING goes wrong   I can also do this   try        do something that may fail except IDontLikeYouException        say please except YouAreTooShortException        stand on a ladder   But if I want to do the same thing inside two different exceptions  the best I can think of right now is to do this   try        do something that may fail except IDontLikeYouException        say please except YouAreBeingMeanException        say please   Is there any way that I can do something like this  since the action to take in both exceptions is to say please    try        do something that may fail except IDontLikeYouException  YouAreBeingMeanException        say please   Now this really won t work  as it matches the syntax for   try        do something that may fail except Exception  e        say please   So  my effort to catch the two distinct exceptions doesn t exactly come through   Is there a way to do this

User · Answer

From Python documentation -  8 3 Handling Exceptions      A try statement may have more than one except clause  to specify   handlers for different exceptions  At most one handler will be   executed  Handlers only handle exceptions that occur in the   corresponding try clause  not in other handlers of the same try   statement  An except clause may name multiple exceptions as a   parenthesized tuple  for example   except  RuntimeError  TypeError  NameError       pass       Note that the parentheses around this tuple are required  because   except ValueError  e  was the syntax used for what is normally   written as except ValueError as e  in modern Python  described   below   The old syntax is still supported for backwards compatibility    This means except RuntimeError  TypeError is not equivalent to   except  RuntimeError  TypeError   but to except RuntimeError as   TypeError  which is not what you want

User · Answer

How do I catch multiple exceptions in one line  except block    Do this   try      may raise specific errors    except  SpecificErrorOne  SpecificErrorTwo  as error      handle error    might log or have some other default behavior      The parentheses are required due to older syntax that used the commas to assign the error object to a name  The as keyword is used for the assignment  You can use any name for the error object  I prefer error personally   Best Practice  To do this in a manner currently and forward compatible with Python  you need to separate the Exceptions with commas and wrap them with parentheses to differentiate from earlier syntax that assigned the exception instance to a variable name by following the Exception type to be caught with a comma    Here s an example of simple usage   import sys  try      mainstuff   except  KeyboardInterrupt  EOFError     the parens are necessary     sys exit 0    I m specifying only these exceptions to avoid hiding bugs  which if I encounter I expect the full stack trace from   This is documented here  https   docs python org tutorial errors html  You can assign the exception to a variable   e is common  but you might prefer a more verbose variable if you have long exception handling or your IDE only highlights selections larger than that  as mine does   The instance has an args attribute  Here is an example   import sys  try      mainstuff   except  KeyboardInterrupt  EOFError  as err       print err      print err args      sys exit 0    Note that in Python 3  the err object falls out of scope when the except block is concluded   Deprecated  You may see code that assigns the error with a comma  This usage  the only form available in Python 2 5 and earlier  is deprecated  and if you wish your code to be forward compatible in Python 3  you should update the syntax to use the new form   import sys  try      mainstuff   except  KeyboardInterrupt  EOFError   err    don t do this in Python 2 6      print err     print err args     sys exit 0    If you see the comma name assignment in your codebase  and you re using Python 2 5 or higher  switch to the new way of doing it so your code remains compatible when you upgrade   The suppress context manager  The accepted answer is really 4 lines of code  minimum   try      do something   except  IDontLikeYouException  YouAreBeingMeanException  as e      pass   The try  except  pass lines can be handled in a single line with the suppress context manager  available in Python 3 4   from contextlib import suppress  with suppress IDontLikeYouException  YouAreBeingMeanException        do something     So when you want to pass on certain exceptions  use suppress

User · Answer

If you frequently use a large number of exceptions  you can pre-define a tuple  so you don t have to re-type them many times     This example code is a technique I use in a library that connects with websites to gather data  ConnectErrs     URLError  SSLError  SocketTimeoutError  BadStatusLine  ConnectionResetError   def connect url  data        do connection and return some data     return received data   def some function var a  var b            try  o   connect url  data      except ConnectErrs as e           do the recovery stuff     blah  do normal stuff you would do if no exception occurred   NOTES     If you  also  need to catch other exceptions than those in the pre-defined tuple  you will need to define another except block    If you just cannot tolerate a global variable  define it in main   and pass it around where needed

User · Answer

One of the way to do this is    try     You do your operations here                            except Exception1   Exception2     ExceptionN         If there is any exception from the given exception list      then execute this block                            else     If there is no exception then execute this block     and another way is to create method which performs task executed by except block and call it through all of the except block that you write    try     You do your operations here                            except Exception1      functionname parameterList  except Exception2      functionname parameterList  except Exception3      functionname parameterList  else     If there is no exception then execute this block    def functionname  parameters         your task      return  expression    I know that second one is not the best way to do this  but i m just showing number of ways to do this thing

User · Answer

From Python Documentation      An except clause may name multiple exceptions as a parenthesized tuple  for example   except  IDontLikeYouException  YouAreBeingMeanException  as e      pass   Or  for Python 2 only   except  IDontLikeYouException  YouAreBeingMeanException   e      pass   Separating the exception from the variable with a comma will still work in Python 2 6 and 2 7  but is now deprecated and does not work in Python 3  now you should be using as

[python] Catch multiple exceptions in one line (except block)

Examples related to python

Examples related to exception

Examples related to exception-handling