write an expression that changes the first item in tuple ( should become ( in the process what is the default for the processing mode argument in file open call what module might you use to store python objects in file without converting them to strings yourself how might you go about copying all parts of nested structure at once when does python consider an object true what is your questtest your knowledgeanswers the built-in len function returns the length (number of contained itemsfor any container object in pythonincluding tuples it is built-in function instead of type method because it applies to many different types of objects in generalbuiltin functions and expressions may span many object typesmethods are specific to single object typethough some may be available on more than one type (indexfor exampleworks on lists and tuples because they are immutableyou can' really change tuples in placebut you can generate new tuple with the desired value given ( )you can change the first item by making new tuple from its parts by slicing and concatenatingt ( , [ :(recall that single-item tuples require trailing comma you could also convert the tuple to listchange it in placeand convert it back to tuplebut this is more expensive and is rarely required in practice--simply use list if you know that the object will require in-place changes the default for the processing mode argument in file open call is ' 'for reading text input for input text filessimply pass in the external file' name the pickle module can be used to store python objects in file without explicitly converting them to strings the struct module is relatedbut it assumes the data is to be in packed binary format in the filejson similarly converts limited set of python objects to and from strings per the json format import the copy moduleand call copy deepcopy(xif you need to copy all parts of nested structure this is also rarely seen in practicereferences are usually the desired behaviorand shallow copies ( alist[:]adict copy()set(aset)usually suffice for most copies an object is considered true if it is either nonzero number or nonempty collection object the built-in words true and false are essentially predefined to have the same meanings as integer and respectively acceptable answers include "to learn python,"to move on to the next part of the book,or "to seek the holy grail tuplesfilesand everything else