Days 1, 2, and 3 have focus on text-based games and programs. Here are some more fun text-based programs to try.
The hailstone pattern is a cool number pattern that for any positive whole number, it will always end in one. It repeats the following steps until it gets to one: if the number is even, it will divide by two. If the number is odd, it will multiply by three and add one.
Here is an example that starts with the number 7:
7
22
11
34
17
52
26
13
40
20
10
5
16
8
4
2
1
It took 16 steps!
How can you make this into a program? It should ask the user to enter a number, output the number at every step, and count how many steps it took to finish.
This will require one thing that you likely haven't seen before: mod (%). Mod can be used to determine if a number is even or odd. Mod is similar to division, but just worries about the remainder. So if you do 7 mod 2, it is asking what the remainder is when you divide 7 by 2. The answer is 1. This is how you can check if a variable called 'number' is even:
if number % 2 == 0:What happens when you enter a really big number? How many steps does it take?
Refer to the finished folder for a complete example.
The San Francisco CoderDojo has done a really fun Tic-Tac-Toe Python project that you can go through. Head to https://github.com/CoderDojoSF/tic-tac-toe and follow the links for Lesson 1 and Lesson 2!
Invent With Python is a free online Python book with some great projects.
Chapter 6 (page 84) in the book shows how to create a text-adventure game called Dragon Realm. Here is the online pdf version of the book.
Invent With Python is a free online Python book with some great projects.
Chapter 9 (page 132) in the book shows how to create the letter and word guessing game Hangman. Here is the online pdf version of the book.
Invent With Python is a free online Python book with some great projects.
Chapter 11 (page 217) in the book shows how to create a number guessing game called Bagels. Here is the description of the game from the book:
Bagels is a simple game you can play with a friend. Your friend thinks up a random 3-digit number with no repeating digits,and you try to guess what the number is. After each guess, your friend gives you clues on how close your guess was. If the friend tells you “bagels”, that means that none of the three digits you guessed is in the secret number. If your friend tells you “pico”, then one of the digits is in the secret number, but your guess has the digit in the wrong place. If your friend tells you “fermi”, then your guess has a correct digit in the correct place. Of course, even if you get a pico or fermi clue, you still don't know which digit in your guess is the correct one.
You can also get multiple clues after each guess. Say the secret number is 456, and your guess is 546. The clue you get from your friend would be “fermi pico pico” because one digit is correct and in the correct place (the digit 6), and two digits are in the secret number but in the wrong place (the digits 4 and 5).
Here is the online pdf version of the book.
Snake is a game where you control an always moving character using the keys. The goal is to hit the target without hitting a wall. If you get the target, your character starts moving faster and the target appears somewhere else. The game ends when you hit the wall.
Here is an example of the game created in Scratch: http://scratch.mit.edu/projects/2627038/
Refer to the finished folder for a complete example.
If you want to make more complex games, there are some additional concepts that you can put to use. The first is using functions (which you have created before) to change variables.
In order for a function to change a variable, you must use the 'global' keyword to let Python know you are using the variable already created outside of the function rather than creating a new one. The [pong finished with function.py](Finished/pong finished with function.py) example uses the following function to reset the ball:
def reset_ball(side):
global ball_x
global ball_speed_x
global ball_speed_y
global score1
global score2
ball_speed_y = 5
if side == "left":
ball_speed_x = -3
score2 = score2 + 1
ball_x = 600
else:
ball_speed_x = 3
score1 = score1 + 1
ball_x = 40Functions are a powerful way to start creating more impressive games.
For the 6 day track we didn't cover using sprites in Pygame because it involves a new concept: classes. A class can be thought of as a blue-print that you can use to create many copies of something. Each copy can have their own set of variables (called properties). In pong there were already a lot of variables to keep track of, what if the game had many more objects in it!
Take a look at [catch the good ones.py](Finished/catch the good ones.py) for an example of a simple game that uses a class. In this game your goal is to catch all the falling green balls and avoid the red ones. (You must also download the red_ball.png and green_ball.png files in the Finished folder.)
There are many sources to learn more about Pygame sprites and creating Python classes. If you are learning on your own, check out a book like Hello World! Computer Programming for Kids and Other Beginners.
Take a look at breakout.py for another game that uses a class. (You must also download the brick.png file in the Finished folder.)
How can you improve this starter game?