the first few steps comments on constructions that are fast or slowbut the main focus of this book is to teach how to write correct programsnot the fastest possible programs deleting data no longer in use python has automatic garbage collectionmeaning that there is no need to delete variables (or objectsthat are no longer in use python takes care of this by itself this is opposed toe matlabwhere explicit deleting sometimes may be required tiphow to deal with long lines if statement in program gets too longit may be continued on the next line by inserting back-slash at the end of the line before proceeding on the next line howeverno blanks must occur after the back-slashthe present introductory book just provides tiny bit of all the functionality that python has to offer an important source of information is the official python documentation website (the python library referencea language referenceand more several excellent books are also available (many with scientific computing focus one exception is langtangen' comprehensive book primer on scientific programming with pythonspringer exercises exercise error messages save copy of the program ball py and confirm that the copy runs as the original you are now supposed to introduce errors in the codeone by one for each error introducedsave and run the programand comment how well python' response corresponds to the actual error when you are finished with one errorre-set the program to correct behavior (and check that it works!before moving on to the next error ainsert the word hello on the empty line above the assignment to bremove the sign in front of the comment initial velocity cremove the sign in the assignment to dchange the reserved word print into pint echange the calculation of to * fchange the line print to print greplace the statement * * * ** by * ( / )* * ** filenametesting_ball py