Python for Absolute Beginners Transcripts
Chapter: Problem solving techniques for writing software
Lecture: Demo: Play until someone wins
0:00 The next thing we need to do, that's not checked off
0:02 is we have to go and play until someone wins.
0:06 So, notice I put some comments in here
0:07 create the board, choose initial player.
0:09 I wanted to put that in there to kind of highlight
0:11 what problem solving bit we were doing.
0:14 Also, I've decided to just call this symbols.
0:16 I don't want that to be super, super long
0:18 until we work with it.
0:19 So here we're going to being doing until
0:24 Well, how do we do that?
0:25 Remember, I said at the beginning
0:27 that until a condition is True or False
0:29 that's going to be a while loop
0:31 and what we have to do is put some kind of test in here
0:34 like check or find winner.
0:37 What we want to do is actually go
0:39 and look through this board
0:41 and see if there's somebody that has X, X, X
0:44 or O, O, O or more tricky X, X, X and things like that.
0:49 We're not going to do that yet, but because that's complicated
0:52 let's write a function and pass the board over there
0:56 and maybe we need to pass some more information.
1:00 For now, I think we're just going to pass the board
1:02 and we'll say yeah, there's a winner
1:03 or something like that, but it could be
1:05 that we want to pass this over so it can say
1:07 you know, you are the winner or computer's the winner.
1:09 We'll have another way to keep track of that actually.
1:11 So, we're going to find a winner.
1:13 Now, notice, this has got red curlies.
1:14 That means find winner doesn't exist yet
1:17 but it will, it will
1:19 and then we're just going to go play a round
1:21 a round like this.
1:24 So we've got to go and create this function.
1:25 Remember, your function stuff from earlier
1:28 we can go and type def, this, and do the bits
1:31 or we could just hit alt, enter in PyCharm
1:34 and say create the function.
1:36 Don't really like that it puts it at the top
1:38 but it's the safest thing it can do
1:39 but it's because the way main works
1:42 it's not necessarily you want main to be the top.
1:44 Okay, so let's just for now return false.
1:48 We are going to take a while to figure out who the winner is.
1:51 This is going to be a really elegant solution
1:54 but it's going to take a little bit of thinking through
1:57 so let's not worry about that now.
1:59 We're not at that step yet
2:01 but it definitely has uncovered the need
2:02 for us to be able to, given a board
2:04 and how it's been played
2:06 determine, has anybody won this just yet.
2:09 Before we worry about the winners
2:11 let's figure out how we might just play a round.
2:13 Now, let's go ahead and run it
2:14 and have a little bit of fun, see what happens.
2:19 Ah, yes, so I had that backwards.
2:21 It's going to do this as long as it finds a winner.
2:24 No, you play the game as long as
2:26 there's not finding a winner.
2:28 There we go.
2:29 Play a round, play a round
2:30 oh my gosh, it's an infinite loop, stop.
2:32 There we go, stop, stop, stop.
2:33 Well, that part works.
2:34 We're doing it over and over as you saw
2:37 and we're checking for a winner.
2:38 Right now we can have a to do
2:41 implement how we check for a winner.