the iscompleteline does simple check at the row specified by the parameter row on the board is considered to be --complete|when every space is filled by box the for loop on line goes through each space in the row if space is blank (which is caused by it having the same value as the blank constant)then the function return false def removecompletelines(board) remove any completed lines on the boardmove everything above them downand return the number of complete lines numlinesremoved boardheight start at the bottom of the board while > the removecompletelines(function will find any complete lines in the passed board data structureremove the linesand then shift all the boxes on the board above that line down one row the function will return the number of lines that were removed (which is tracked by the numlinesremoved variableso that this can be added to the score the way this function works is by running in loop starting on line with the variable starting at the lowest row (which is boardheight whenever the row specified by is not completey will be decremented to the next highest row the loop finally stops once reaches - if iscompleteline(boardy)remove the line and pull boxes down by one line for pulldowny in range( - )for in range(boardwidth)board[ ][pulldownyboard[ ][pulldowny- set very top line to blank for in range(boardwidth)board[ ][ blank numlinesremoved + note on the next iteration of the loopy is the same this is so that if the line that was pulled down is also completeit will be removed elsey - move on to check next row up return numlinesremoved the iscompleteline(function will return true if the line that is referring to is complete in that casethe program needs to copy the values of each row above the removed line to the next lowest line this is what the for loop on line does (which is why its call to the range(function begins at yrather than also note that it uses the three argument form of