You just need two try/finally blocks: Screen.Cursor:= crHourGlass; try Obj:= TSomeObject.Create; try // do something finally Obj.Free; end; finally Screen.Cursor:= crDefault; end; The guideline to follow is that you should use finally rather than except for protecting resources. As you have observed, if you attempt to do it with except then you are forced to … Read more
Nope. A Python lambda can only be a single expression. Use a named function. It is convenient to write a generic function for converting types: def tryconvert(value, default, *types): for t in types: try: return t(value) except (ValueError, TypeError): continue return default Then you can write your lambda: lambda v: tryconvert(v, 0, int) You could … Read more
If you want the response to raise an exception for a non-200 status code use response.raise_for_status(). Your code would then look like: testURL = ‘http://httpbin.org/status/404’ def return_json(URL): response = requests.get(testURL) try: response.raise_for_status() except requests.exceptions.HTTPError as e: # Whoops it wasn’t a 200 return “Error: ” + str(e) # Must have been a 200 status code … Read more
Yes you can catch all errors like so: try: print(555) except Exception as e: print(“type error: ” + str(e)) For the stack trace I usually use the traceback module: import traceback try: print(555) except Exception as e: print(“type error: ” + str(e)) print(traceback.format_exc())
try: do_something() except: pass You will use the pass statement. The pass statement does nothing. It can be used when a statement is required syntactically but the program requires no action.
try statements do not create a new scope, but text won’t be set if the call to url lib.request.urlopen raises the exception. You probably want the print(text) line in an else clause, so that it is only executed when there is no exception. try: url = “http://www.google.com” page = urllib.request.urlopen(url) text = page.read().decode(‘utf8’) except (ValueError, … Read more
From the Python documentation A finally clause is always executed before leaving the try statement, whether an exception has occurred or not. When an exception has occurred in the try clause and has not been handled by an except clause (or it has occurred in a except or else clause), it is re-raised after the … Read more
Because finally statements are guaranteed to be executed (well, presuming no power outage or anything outside of Python’s control). This means that before the function can return, it must run the finally block, which returns a different value. The Python docs state: When a return, break or continue statement is executed in the try suite … Read more
Do a while True inside your for loop, put your try code inside, and break from that while loop only when your code succeeds. for i in range(0,100): while True: try: # do stuff except SomeSpecificException: continue break
try: doSomething() except Exception: pass or try: doSomething() except: pass The difference is that the second one will also catch KeyboardInterrupt, SystemExit and stuff like that, which are derived directly from BaseException, not Exception. See documentation for details: try statement exceptions However, it is generally bad practice to catch every error – see Why is … Read more