holds reference to rect object which stores the location and size of the baddie the call to the pygame rect(constructor function has four parametersthe -coordinate of the top edge of the areathe -coordinate of the left edge of the areathe width in pixelsand the height in pixels the baddie needs to appear randomly across the top of the windowso pass random randint( windowwidth-baddiesizefor the -coordinate of the left edge the reason you pass windowwidth-baddiesize instead of windowwidth is because this value is for the left edge of the baddie if the left edge of the baddie is too far on the right side of the screenthen part of the baddie will be off the edge of the window and not visible the bottom edge of the baddie should be just above the top edge of the window the ycoordinate of the top edge of the window is to put the baddie' bottom edge thereset the top edge to baddiesize the baddie' width and height should be the same (the image is square)so pass baddiesize for the third and fourth argument the rate of speed that the baddie moves down the screen is set in the 'speedkey set it to random integer between baddieminspeed and baddiemaxspeed baddies append(newbaddieline will add the newly created baddie data structure to the list of baddie data structures the program will use this list to check if the player has collided with any of the baddiesand to know where to draw baddies on the window moving the player' character move the player around if moveleft and playerrect left playerrect move_ip(- playermoverate the four movement variables moveleftmoverightmoveup and movedown are set to true and false when pygame generates the keydown and keyup eventsrespectively if the player' character is moving left and the left edge of the player' character is greater than (which is the left edge of the window)then playerrect should be moved to the left you'll always move the playerrect object by the number of pixels in playermoverate to get the negative form of an integermultiple it by - on line since is stored in playermoveratethe expression - playermoverate evaluates to - post questions to