decision structures objectives to understand the programming pattern simple decision and its implementation using python if statement to understand the programming pattern two-way decision and its implementation using python if-else statement to understand the programming pattern multi-way decision and its implementation using python if-elif-else statement to understand the idea of exception handling and be able to write simple exception handling code that catches standard python run-time errors to understand the concept of boolean expressions and the bool data type to be able to readwriteand implement algorithms that employ decision structuresincluding those that employ sequences of decisions and nested decision structures simple decisions so farwe have mostly viewed computer programs as sequences of instructions that are followed one after the other sequencing is fundamental concept of programmingbut alone it is not sufficient to solve every problem often it is necessary to alter the sequential flow of program to suit the needs of particular situation this is done with special statements known as control structures in this we'll take look at decision structureswhich are statements that allow program to execute different sequences of instructions for different caseseffectively allowing the program to "choosean appropriate course of action