lists have methods too in the last section we took look at some of the methods for manipulating string objects like stringslists are also objects and come with their own set of "extraoperations since this is primarily concerned with text-processingwe'll save the detailed discussion of various list methods for for later howeveri do want to introduce one important list method herejust to whet your appetite the append method can be used to add an item at the end of list this is often used to build list one item at time here' fragment of code that creates list of the squares of the first natural numberssquares [for in range( , )squares append( *xin this example we start with an empty list ([]and each number from to is squared and appended to the list when the loop is donesquares will be the list[ this is really just the accumulator pattern at work againthis time with our accumulated value being list with the append method in handwe can go back and address weakness in our little decoder program as we left itour program used string variable as an accumulator for the decoded output message because strings are immutablethis is somewhat inefficient the statement message message chr(codenumessentially creates complete copy of the message so far and tacks one more character on the end as the we build up the messagewe keep recopying longer and longer stringjust to add single new character at the end one way to avoid recopying the message over and over again is to use list the message can be accumulated as list of characters where each new character is appended to the end of the existing list rememberlists are mutableadding at the end of the list changes the list "in place,without having to copy the existing contents over to new object once we have accumulated all the characters in listwe can use the join operation to concatenate the characters into string in one fell swoop here' version of the decoder that uses this more efficient approach numbers text py program to convert sequence of unicode numbers into string of text efficient version using list accumulator def main()print("this program converts sequence of unicode numbers into"print("the string of text that it represents \ "