Pygame (Python Game Development) Tutorial - 21 - How to Lengthen the Snake Video Lecture | Pygame (Python Game Development): Create Awesome Games - Front-End Programming

hey guys what's going on welcome to your
21st pygame tutorial video in this video
we're going to be working on is making
our snake a little longer when he eats
an apple as all as well as when he runs
into himself that's a big deal so uh
first of all to make the snake get a
little longer every time he eats an
apple oh yeah they're just kind of
scroll down to where we redefine Apple
X&Y so where we've redefined Apple x and
y is after lead X is the same as Apple
random X and then leap wise random Apple
Y so that's when we've run over an apple
so or eaten an apple so at that point is
when we actually will allow our snake to
get a little longer and the variable for
that let me find that snake length so we
would just say snake length plus equals
1 and right now I think our starting
length was pretty long just to show it
so now we'll start at 1 again so just
scroll up to the top and change that to
1 if you had changed that to 10 and
we'll save it run that and so here we
are
this Apple there we go so we ate that
Apple we're getting a little longer cool
a little longer this can be a challenge
oh my guys got it anyway you guys get
the point so now we're getting a little
longer but we still can run into
ourselves especially noted by just going
back and forth like this you know that
you're being allowed to run into
yourself so we need to fix that so how
might we know that we've run into
ourselves so just like running into the
Apple where we could maybe have a larger
Apple um but we got away with having a
smaller Apple right now as far as
knowing like whether the XS and the Y's
are crossed over so to speak the snake
hitting itself you could do it a hard
way and you could say like you know if
the if any you know you could measure
where all of the snake is or sigh like
that and you could do it kind of weird
but if you the easiest way that I can
think of is to ask the question if the
snake head has the exact same
coordinates as any other segment in the
snake that means we've crashed and
that's it we just have to ask that one
simple question so to ask that question
where we're going to ask that question
is gonna be really before we get before
we even draw the snake really it doesn't
matter you could do it before after if
you draw the snake then you'll see the
full collision as opposed to like you'll
have collided and gone through it as
opposed to just hitting like the front
of it but I'll call it before it doesn't
really matter in the at the end of the
day so to know for sure if we hit
ourselves um we would just ask for each
segment segment in snake list and that
would be anything up to the last element
so if you don't really know your list
comprehension kind of stuff here like to
to reference anything from the after the
first element you would say snake list
you know 1 : so everything from the
first element onward and ignoring the
first element basically and anything to
the like negative 1 is the last element
if you put negative 1 and we need to put
negative 2 it's like the second to last
element so we're saying is analyze
everything up to the last element
because the last element in the list
that's where the snake head is right so
we don't care we're asking the question
if the snake head is equal to anything
else so obviously we if we let it go all
the way into the snake list so if we
just said for everything for each
segment is snake list the head would
equal the head so then we would
obviously we would say oh you've crashed
even though you had it so : negative 1
and then what we're going to say is if
each segment doubly equals
snake head so if each of the snake if
the if the segment is identical to the
same coordinate s the snake head then we
have a collision so if we if that's the
case game over equals game over just one
equal sign true
okay so let's save that and let's run
that bring this over and tag this man
we're boss and snake at the moment
oh my goodness not anymore I spoke too
soon guys it is anyway we'll play in
snake and let's just go in RSA so we
turned in on ourselves game over
see you to play again Q to quit and we
can do it right now because we're only
one long but let's run over ourselves
really quick after we get this Apple if
I ever get it mmm there we go run over
ourselves see where I guess actually
because we're too they would they just
flip their positions so that would be
why that's allowing us to do that but
let's get three and now we turn into
ourselves and again we game over so
we're pretty confident that now we have
the code required to analyze whether or
not we're actually like crashing into
ourselves so anyway so we have that and
actually now would be pretty much one of
the first times we've AK we've found
ourselves at a pretty much fully
functional snake game so congratulations
on that but there's actually a lot of
other things that we need to do this
snake game to make it better
and there's a lot of other things to PI
game too that we definitely definitely
want to cover but let's give yourself
somewhat of a pat on the back because
this is a I would say a pretty fully
functional game so anyway lots to still
cover here but hopefully you guys have
enjoyed up to this point as always
thanks for watching