python for artificial intelligence is an expression that evaluates to either true or false for each eand fe is an expression that will be evaluated for each value of for which cond returns true the result can go in list or used in another iterationor can be called directly using next the procedure next takes an iterator returns the next element (advancing the iteratorand raises stopiteration exception if there is no next element the following shows simple examplewhere user input is prepended with [ * for in range( if % == [ ( * for in range( if % == next( next( next( list( [ next(atraceback (most recent call last)file ""line in stopiteration notice how list(acontinued on the enumerationand got to the end of it comprehensions can also be used for dictionaries the following code creates an index for list aa [" "," ","bar"," "," ","aaaaa"ind { [ ]: for in range(len( ))ind {' ' ' ' 'bar' ' ' 'aaaaa' ind[' ' which means that 'bis the rd element of the list the assignment of ind could have also be written asind {val: for ( ,valin enumerate( )where enumerate returns an iterator of (indexvaluepairs functions as first-class objects python can create lists and other data structures that contain functions there is an issue that tricks many newcomers to python for local variable in functionthe function uses the last value of the variable when the function is version june