on unix-based systems (including mac os and linux)your working directory might be in /usr/home and be created by mkdir command in shell window or file explorer gui specific to your platformbut the same concepts apply the cygwin unix-like system for windows is similar toothough your directory names may vary (/home and /cygdrive/ are candidatesyou can store your code in python' install directory too ( :\python on windowsto simplify some command lines before setting pathbut you probably shouldn' --this is for python itselfand your files may not survive move or uninstall once you've made your working directoryalways start there to work along with the examples in this book the prompts in this book that show the directory that ' running code in will reflect my windows laptop' working directorywhen you see \codeor %think the location and name of your own directory what not to typeprompts and comments speaking of promptsthis book sometimes shows system prompts as generic %and sometimes in full :\codewindows form the former is meant to be platform agnostic (and derives from earlier editionsuse of linux)and the latter is used in windowsspecific contexts also add space after system prompts just for readability in this book when usedthe character at the start of system command line stands for the system' promptwhatever that may be on your machine for instanceon my machine stands for :\codein windows command promptand just in my cygwn install to beginnersdon' type the character (or the :\code system prompt it sometimes stands foryou see in this book' interaction listings yourself--this is text the system prints type just the text after these system prompts similarlydo not type the and characters shown at the start of lines in interpreter interaction listings--these are prompts that python displays automatically as visual guides for interactive code entry type just the text after these python prompts for instancethe prompt is used for continuation lines in some shellsbut doesn' appear in idleand shows up in some but not all of this book' listingsdon' type it yourself if it' absent in your interface to help you remember thisuser inputs are shown in bold in this bookand prompts are not in some systems these prompts may differ (for instancethe pypy performancefocused implementation described in uses four-character and )but the same rules apply also keep in mind that commands typed after these system and python prompts are meant to be run immediatelyand are not generally to be saved in the source files we will be creatingwe'll see why this distinction matters ahead in the same veinyou normally don' need to type text that starts with character in listings in this book--as you'll learnthese are commentsnot executable code except when is used to introduce directive at the top of script for unix or the python how you run programs