Sometimes, you'll want to display a simple error message for the user. This will be friendly than many of the standard errors and you can provide additional clues for the user to fix the problem. You could add a try/catch block that indicates 'Sorry, there was a problem reading from the file '. As an example, you may write a function that reads a specific type of file such as a text file. Then, add additional try/except blocks to catch errors where the user will need additional information. You'll always want to have one around the 'top-level' of your code. Over time, you'll add more and more try/except blocks to your programs. Soon, we'll learn how to display errors in 'alert boxes' similar to those you have seen in most software programs. If you're not sure which part of the code generated the exception, you can just add more 'try/except' blocks around suspicious code until you isolate the problem.įor now we'll be adding 'print' statements to our code these will only appear when we are running in the IDE or in 'command line mode' (more on this later).

If you capture the 'exception' then you'll know what happened. If they generate an exception, the program will simple stop and you'll have no idea why. This is actually very important for when we start calling external programs and more complex libraries. Try the example below that contains a 'divide-by-zero' error. If an error occurs in the code in the 'try' section, then the code in the 'except' will be called. Your code goes between the 'try:' and 'except:' keywords and then you put the error message after the 'except:'.

You just need to put your code into a 'try/except' block. Like many things in Python, exception handling is very easy. In Python this is referred to as 'Exception Handling'. Because of this problems and others, we must prepare our programs to handle 'error conditions'. When communicating with web services we may find that their server is down and not responding to our requests. When working with files, you'll encounter problems with the data in the file not following the standard so our code cannot read it correctly. Invalid port range specified for debugging Java extensions.Managing Errors: Exception Handling IntroductionĪll programs will create errors at some point. Java debugging ports have not been specified. Failed to update the log settings on machine ''''.įailed to clean configuration store.

Arcgis file handler error