Circles And Squares.
from turtle import *
bgcolor('black')
a = Turtle()
a.speed(0)
a.hideturtle()
b = Turtle()
b.speed(0)
b.hideturtle()
colorA = textinput('pencolor a',"what is your name?:")
colorB = textinput('pencolor b',"what is your name?:")
size = 0
while True:
b.pencolor(colorB)
b.forward(size*3)
b.left(91)
a.pencolor(colorA)
a.forward(size*10)
a.circle(size, 360)
a.left(500)
size += 1
More circles
import turtle as t
t.bgcolor('black')
t.hideturtle()
size = -300
t.speed(0)
while True:
if size % 2 == 0:
t.pencolor('cyan')
else:
t.pencolor('magenta')
t.circle(size*3)
size += 1
First make a painting program where you can chose colors and draw rectangles
import pgzrun
WIDTH = 800
HEIGHT = 800
elf = Actor('c1')
x = 0
y = 0
color = None
drop = []
size = 40
def update():
global color,size
if keyboard.W:
elf.y -= 5
if keyboard.S:
elf.y += 5
if keyboard.D:
elf.x += 5
if keyboard.A:
elf.x -= 5
if keyboard.C:
screen.clear()
if keyboard.SPACE and color != None:
drop.append([color, Rect(elf.x, elf.y, size, size)])
if keyboard.K_1:
color = (255,0,0)
if keyboard.K_2:
color = (25,41, 88)
if keyboard.K_8:
size += 1
if keyboard.K_9:
size -= 1
def draw():
screen.clear()
elf.draw()
for pixel in drop:
screen.draw.rect(pixel[1],pixel[0])
if color != None:
screen.draw.rect(Rect(elf.x,elf.y,size,size), color)
pgzrun.go()
Same program but making a Pixel class instead of a list with color and rect.
import pgzrun
WIDTH = 800
HEIGHT = 800
class Pixel:
def __init__(self, color, x, y, size):
self.color = color
self.rect = Rect(x,y,size,size)
def draw(self):
screen.draw.rect(self.rect, self.color)
elf = Actor('c1')
x = 0
y = 0
color = None
drop = []
size = 40
def update():
global color,size
if keyboard.W:
elf.y -= 5
if keyboard.S:
elf.y += 5
if keyboard.D:
elf.x += 5
if keyboard.A:
elf.x -= 5
if keyboard.C:
screen.clear()
if keyboard.SPACE and color != None:
pixel = Pixel(color, elf.x, elf.y, size)
drop.append(pixel)
if keyboard.K_1:
color = (255,0,0)
if keyboard.K_2:
color = (25, 41, 88)
if keyboard.K_8:
size += 1
if keyboard.K_9:
size -= 1
def draw():
screen.clear()
elf.draw()
for pixel in drop:
pixel.draw()
if color != None:
screen.draw.rect(Rect(elf.x,elf.y,size,size), color)
pgzrun.go()
Go back in the book and re-read the class chapter.
Try out some ideas with a class, just to understand better what self is, for example play around with this Point class, try to add move_right or move_up methods.
class Point:
def __init__(self, x, y):
self.x = x
self.y = y
def move(self,x,y):
self.x = x
self.y = y
def move_left(self):
self.x -= 1
def show(self):
print(self.x, self.y)
def equal(self, other_point):
if self.x == other_point.x and self.y == other_point.y:
return True
return False
p1 = Point(10,20)
p2 = Point(30,40)
p3 = Point(10,20)
p3.move(50,60)
p1.show()
p2.show()
p3.move_left()
p3.show()
print(p3.equal(p1))
Completely unrelated and just for fun, make a triangle like pattern:
while True:
for i in range(0,10):
print(':3'* i)
for i in range(10,0,-1):
print(':D' * i)
Prints infinite sequence of smilies
:3
:3:3
:3:3:3
:3:3:3:3
:3:3:3:3:3
:3:3:3:3:3:3
:3:3:3:3:3:3:3
:3:3:3:3:3:3:3:3
:3:3:3:3:3:3:3:3:3
:D:D:D:D:D:D:D:D:D:D
:D:D:D:D:D:D:D:D:D
:D:D:D:D:D:D:D:D
:D:D:D:D:D:D:D
:D:D:D:D:D:D
:D:D:D:D:D
:D:D:D:D
:D:D:D
:D:D
:D
:3
:3:3
:3:3:3
:3:3:3:3
:3:3:3:3:3
:3:3:3:3:3:3
...
Make 3 actors you can pick up and drop them wherever you hit SPACE.
import pgzrun
WIDTH = 500
HEIGHT = 500
king = Actor('c2')
elf = Actor('c1')
flower = Actor('flower')
rock = Actor('rock')
king.x = 480
king.y = 125
flower.y = 380
flower.x = 480
rock.x = 480
rock.y = 250
drop = []
speed = 5
def update():
global speed
if keyboard.W:
elf.y -= speed
if keyboard.S:
elf.y += speed
if keyboard.D:
elf.x += speed
if keyboard.A:
elf.x -= speed
if keyboard.C:
screen.clear()
if elf.colliderect(king):
elf.image=king.image
speed = 2
if elf.colliderect(rock):
elf.image=rock.image
speed = 1
if elf.colliderect(flower):
elf.image=flower.image
speed = 10
if keyboard.SPACE and elf.image != 'c1':
a = Actor(elf.image)
a.x = elf.x
a.y = elf.y
drop.append(a)
elf.image='c1'
speed = 5
def draw():
screen.clear()
elf.draw()
king.draw()
flower.draw()
rock.draw()
for d in drop:
d.draw()
pgzrun.go()
Find Waldo, here are two different implementations of the game, one uses dictionaries and one doesnt.
In this game, one of the actors has his back turned, and the purpose of the game is to find them.
We are using this example to practice lists, using for element in list and for i in range(len(list)), and overusing iterating over the list to find a matching element.
import pgzrun
import random
WIDTH = 800
HEIGHT = 800
elf = Actor('c1')
elf.x = 400
elf.y = 400
drop = []
def on_key_down(key):
if key == keys.SPACE:
found = False
for i in drop:
if i.image == 'c2-back':
found = True
if not found:
a = Actor('c2-back')
a.x = random.randint(0,1500)
a.y = random.randint(0,1500)
drop.append(a)
for i in range(100):
a = Actor('c2')
a.x = random.randint(0,2000)
a.y = random.randint(0,2000)
drop.append(a)
if key == keys.P:
for i in drop:
if i.image == 'c2-back':
i.x = random.randint(elf.x - 200,elf.x + 200)
i.y = random.randint(elf.y - 200,elf.y + 200)
waldo_found = False
def update():
global waldo_found
if keyboard.W:
for x in range(len(drop)):
i = drop[x]
i.y += 5
if keyboard.S:
for a in range(len(drop)):
drop[a].y -= 5
if keyboard.A:
for i in drop:
i.x += 5
if keyboard.D:
for i in drop:
i.x -= 5
for i in drop:
if i.image == 'c2-back' and elf.colliderect(i):
waldo_found = True
def draw():
screen.fill('black')
elf.draw()
for i in drop:
i.draw()
if waldo_found == True:
screen.draw.text(" YOU HAVE FOUND WALDO ", (10,10))
pgzrun.go()
A second implementation where we use a waldo variable so we dont have to scan the list of actors so many times, and also we move the elf instead of moving all the actors. And we use a dictionary with positions to try to avoid adding an actor close to already existing one.
import pgzrun
import random
WIDTH = 800
HEIGHT = 800
elf = Actor('c1')
elf.x = 400
elf.y = 400
drop = []
waldo = Actor('c2-back')
seen = {}
def on_key_down(key):
if key == keys.SPACE:
waldo.x = random.randint(0,WIDTH)
waldo.y = random.randint(0,HEIGHT)
place = str(int(waldo.x/50)) + "_" + str(int(waldo.y/100))
seen[place] = True
for i in range(100):
x = random.randint(0,WIDTH)
y = random.randint(0,HEIGHT)
place = str(int(x/50)) + "_" + str(int(y/100))
if place not in seen:
a = Actor('c2')
a.x = x
a.y = y
drop.append(a)
seen[place] = True
waldo_found = False
def update():
global waldo_found
if keyboard.W:
elf.y -= 5
if keyboard.S:
elf.y += 5
if keyboard.A:
elf.x -= 5
if keyboard.D:
elf.x += 5
if waldo.colliderect(elf):
waldo_found = True
def draw():
screen.fill('black')
elf.draw()
for i in drop:
i.draw()
waldo.draw()
if waldo_found == True:
screen.draw.text(" YOU HAVE FOUND WALDO ", (10,10))
pgzrun.go()
Pacman, make things move around, stop when they hit something
import random
import pgzrun
WIDTH = 600
HEIGHT = 600
game_over = False
lives = 3
obsticles = [
Rect(100,100,20,20),
Rect(200,200,100,200),
]
class Mover:
def __init__(self, image, x, y, direction):
self.actor = Actor(image)
self.direction = direction
self.actor.x = x
self.actor.y = y
self.counter = 0
def draw(self):
self.actor.draw()
def update(self):
orig_x = self.actor.x
orig_y = self.actor.y
self.counter += 1
if self.counter > 120 and self.actor.image == "c2":
self.direction = random.choice(['up','down','left','right'])
self.counter = 0
if self.direction == 'up':
self.actor.y -= 1
if self.direction == 'down':
self.actor.y += 1
if self.direction == 'left':
self.actor.x -= 1
if self.direction == 'right':
self.actor.x += 1
if self.actor.x > WIDTH:
self.actor.x = 0
if self.actor.x < 0:
self.actor.x = WIDTH
if self.actor.y > HEIGHT:
self.actor.y = 0
if self.actor.y < 0:
self.actor.y = HEIGHT
hit_wall = False
for o in obsticles:
if self.actor.colliderect(o):
self.actor.x = orig_x
self.actor.y = orig_y
hit_wall = True
break
if hit_wall and self.actor.image == "c2":
self.direction = random.choice(['up','down','left','right'])
pacman = Mover("c1", 10, 10, 'up')
movers = [pacman,
Mover("c2", 100, 40, 'up'),
Mover("c2", 100, 50, 'up'),
Mover("c2", 100, 60, 'up'),
Mover("c2", 100, 70, 'up')
]
def update():
global lives,game_over
if keyboard.W:
pacman.direction = 'up'
if keyboard.S:
pacman.direction = 'down'
if keyboard.A:
pacman.direction = 'left'
if keyboard.D:
pacman.direction = 'right'
for m in movers:
m.update()
for o in movers:
if pacman.actor.colliderect(o.actor) and o != pacman:
lives -= 1
pacman.actor.x = 0
pacman.actor.y = 0
if lives < 0:
game_over = True
def draw():
screen.fill('black')
for o in obsticles:
screen.draw.filled_rect(o,(255,0,0))
screen.draw.text('lives: ' + str(lives), (10,10))
if game_over == True:
screen.fill('royalblue')
screen.draw.text('GAME OVER YOU LOST',(10,10))
for m in movers:
m.draw()
pgzrun.go()
First lets discuss a bit about the difference between c++ and python. For example, lets examine what happens with the following program:
while True:
print("hello world")
If you save it in the file hello.py, and you have to start it with python hello.py. Python is a program on its own, which will load the hello.py file and execute it line by line. The python program is called interpreter because it interprets the code, kind of like when you read a program, trying to find out what it does, you interpret the code in your head and evaluate it.
c and c++ on the other hand are compiled languages, you need a program gcc for c and g++ for c++ to transform your source code to machine code, that your computer will directly run, instruction by instruction, gcc and g++ are compilers.
Lets start where everything starts, print "Hello World". Save the following program in a file hello.cpp (cpp for c plus plus).
#include <iostream>
using namespace std;
int main(void) {
cout << "Hello World " << endl;
}
Now lets compile it, g++ -o hello hello.cpp will make a program hello that you will be able to execute by running ./hello you see it is very different, you run directly hello which will make your computer execute its instructions one by one, which is very different than running python to load your hello.py, in the python case your computer is running the python executable which loads your hello.py and interprets it line by line.
int main() declares the main function, each c/c++ program must have a main() function, thats where your program starts, unlike python, where it starts from the top of the file. You can think of your processor jumping to the address of the main function in memory, as we spoke in the previous lessons, in the computer's memoruy code is data, and data is code.
cout means character output and << means pour into the cout whatever follows, e.g. cout << 5 will just print 5, cout "hello" will print hello, cout << 5 << "hello" will print 5hello, and endl inserts the newline character \n.
using namespace std; is similar to from turtle import *, we will get into it later
And very importantly you c++ does not care about your spaces, the following program compiles just fine
#include <iostream>
using namespace std;int main(void) {cout << "Hello World " << endl;}
Each code block is surrounded by {} and each statement ends with ; and thats it
Try out the following programs, and just experiment with them using your python knowledge. (hint: int means integer)
#include <iostream>
using namespace std;
int main(void) {
int i = 1000;
while(i) {
if (i < 500) {
cout << "HIII" << endl;
} else {
cout << "Hello World " << i << endl;
}
i--;
}
}
#include <iostream>
using namespace std;
int main(void) {
for (int i = 1000; i >= 0 ; i--) {
if (i < 500) {
cout << "HIII " << i << endl;
} else {
cout << "Hello World " << i << endl;
}
}
return 0;
}
Write the same code with for and while loops.
#include <iostream>
using namespace std;
int main(void) {
int x = 3;
while(x < 3000000){
cout << x << endl;
x = x+3;
}
return 0;
}
#include <iostream>
using namespace std;
int main(void) {
for (int x = 0; x < 3000000; x = x + 3) {
cout << x << endl;
}
return 0;
}
#include <iostream>
using namespace std;
int main(void) {
for (int x = 10; x > 0; x = x - 1) {
cout << x << endl;
}
return 0;
}
#include <iostream>
using namespace std;
int main(void) {
int x = 10;
while(x > 0){
cout << x << endl;
x -= 1;
}
return 0;
}
#include <iostream>
using namespace std;
int main(void) {
int x = 0;
while (x < 10) {
cout << x << endl;
x+=1;
}
return 0;
}
#include <iostream>
using namespace std;
int main(void) {
for(int x = 0; x < 10; x += 1){
cout << x << endl;
}
return 0;
}