delve into the worlds of unicode encodings or binary data for some readers' preview may sufficeand others may wish to file this away for future reference if you ever need to care about processing either of thesethoughyou'll find that python' string models provide the support you need string changes in one of the most noticeable changes in the python line is the mutation of string object types in nutshell ' str and unicode types have morphed into ' bytes and str typesand new mutable bytearray type has been added the bytear ray type is technically available in python and too (though not earlier)but it' back-port from and does not as clearly distinguish between text and binary content in especially if you process data that is either unicode or binary in naturethese changes can have substantial impacts on your code as general rule of thumbhow much you need to care about this topic depends in large part upon which of the following categories you fall intoif you deal with non-ascii unicode text--for instancein the context of internationalized domains like the webor the results of some xml and json parsers and databases--you will find support for text encodings to be different in xbut also probably more directaccessibleand seamless than in if you deal with binary data--for examplein the form of image or audio files or packed data processed with the struct module--you will need to understand ' new bytes object and ' different and sharper distinction between text and binary data and files if you fall into neither of the prior two categoriesyou can generally use strings in much as you would in xwith the general str string typetext filesand all the familiar string operations we studied earlier your strings will be encoded and decoded by using your platform' default encoding ( asciior utf- on windows in the --sys getdefaultencoding gives your default if you care to check)but you probably won' notice in other wordsif your text is always asciiyou can get by with normal string objects and text files and can avoid most of the following story for now as we'll see in momentascii is simple kind of unicode and subset of other encodingsso string operations and files generally "just workif your programs process only ascii text even if you fall into the last of the three categories just mentionedthougha basic understanding of unicode and ' string model can help both to demystify some of the underlying behavior nowand to make mastering unicode or binary data issues easier if they impact you later unicode and byte strings