dealing with errors in this defining problems in communication with python understanding error sources handling error conditions specifying that an error has occurred developing your own error indicators performing tasks even after an error occurs ost application code of any complexity has errors in it when your application suddenly freezes for no apparent reasonthat' an error seeing one of those obscure message dialog boxes is another kind of error howevererrors can occur that don' provide you with any sort of notification an application might perform the wrong computation on series of numbers you provideresulting in incorrect output that you may never know about unless someone tells you that something is wrong or you check for the issue yourself errors need not be consistenteither you may see them on some occasions and not on others for examplean error can occur only when the weather is bad or the network is overloaded in shorterrors occur in all sorts of situations and for all sorts of reasons this tells you about all sorts of errors and what to do when your application encounters them it shouldn' surprise you that errors occur -applications are written by humansand humans make mistakes most developers call application errors exceptionsmeaning that they're the exception to the rule because exceptions do occur in applicationsyou need to detect and do something about them whenever possible the act of detecting and processing an exception is called error handling or exception handling in order to properly detect errorsyou need to know about error sources and why errors occur in the first place when you do detect the erroryou must process it by catching the exception catching an exception means examining it and possibly doing something about it soanother part of this is about discovering how to perform exception handling in your own application