Pygame (Python Game Development) Tutorial - 20 - More Snake Functionality Video Lecture | Pygame (Python Game Development): Create Awesome Games - Front-End Programming

hey guys what's going on welcome to
another Python programming tutorial with
PI game where we left off we've got a
snake he's running around is eatin
apples but he's not getting any longer
and so we know our end goal is to have a
list that contains all the X's starting
X's and Y's for the segments of our
snake and right now we're basically
clearing that list every time so arsenic
is only ever always one like bit long
but we want to change that so the way
that we can start to handle that is by
first we need to move snake list because
right now each time this while loop runs
its clearing snake list because we're
redefining snake list we definitely want
to clear and redefine snake head every
time but not snake list so let's go
ahead and cut snake list there and
really we just need it to be defined
somewhere here in the top of game loop
so I'll just define it right here so
snake list empty list we'll just put up
there now uh we'll come down here and
first I suppose we can make sure
everything runs but everything should
run at this point but yeah so as you can
see though we have a slight problem and
it's that our snake just keeps getting
longer and longer let's go ahead see if
we can get this Apple anybody think it's
possible oh my goodness I was going to
try and do it not cross over and I
already failed anyway so we can see what
part of the problem is here is that our
snake just continues getting not only
getting longer and longer since we put a
list up there so we don't want to clear
the list every time but we're having
trouble putting that list up there so
what do we need to do well well we need
to do is we need to call the length of
the list every time I ask or query the
length of the list and then that way we
can make an educated decision on whether
or not we need to chop up that list and
make it a little bit shorter or not
which is going to be most of the time we
do so first of all how would we do that
so we up here we've got snake list and
we know that when we start the list the
length will be 1 right so now I have one
segment but then as time goes on when we
run over an apple the length would be 2
3 4 and so on so we
other we would start let's say a snake
length and we'll call that one it starts
at one and then what we would do is
whenever we run over an apple
what would we actually what we want to
do for real is we would add one
basically to the length of our snake but
for now let us just um really before we
draw the snake we have to call this
question so basically if Len of
snake list so the length of the list of
all of these items in our snake list is
greater than the snake length so if
that's great if there's more items in
the list then we're allowed to have in
the length of our snake what do we want
to do well we want to delete snake list
element zero so the first element net
list because every time we have pen to
that list
it basically appends you know on the end
right that's the whole point of append
so so append adds to the end of the list
so the older elements will be at the
front of the list so we'd want to get
rid of the very first element so let's
go ahead save and run that and see if
our snake acts accordingly and it does
so by the same token we could say we can
go up to the top here and we could say
oh no it would be in our game with snake
length ten okay so now our snake will be
allowed to get ten long possibly so like
this and now he's ten long but you can
see operates how we would expect snake
to operate so that's good
okay so now what we have is snake it's a
snake list and all of that that's great
but as we eat the apple doesn't add
anything to it but we'll work on that
probably in the next video and then also
if we run into ourselves it doesn't
really seem to matter
you can run into ourselves while we
whine it's not a big deal so obviously
that needs to be fixed so that's what
we're going to be doing in the next
video so stay tuned for that thank you
for watching