Segue 5

1. Basics

This is what a basic python script looks like.
# Hello world print "Hello World!" print "Hello Again" print "I like typing this." print "This is fun." print 'Yay! Printing.' print "I'd much rather you 'not'." print 'I "said" do not touch this.'
Python has many unique characteristics including algebra.
# Easy Python print "It's easy to print a Python script" i = 42 i = i + 1 print i x = 3 + 4j y = 2 - 3j z = x + y print z s = "A string consists of characters" print s[5] print "Python"[-2]
Python uses all the familiar Maths operations.
# Math print "MATH" print "I will now count my chickens:" print "Hens", 25 + 30 / 6 # 30 print "Roosters", 100 - 25 * 3 % 4 # 97 print "Now I will count the eggs:" print 3 + 2 + 1 - 5 + 4 % 2 - 1 / 4 + 6 # 7 print "Is it true that 3 + 2 < 5 - 7?" print 3 + 2 < 5 - 7 # False print "What is 3 + 2?", 3 + 2 # 5 print "What is 5 - 7?", 5 - 7 # -2 print "Oh, that's why it's False." print "How about some more." print "Is it greater?", 5 > -2 # True print "Is it greater or equal?", 5 >= -2 # True print "Is it less or equal?", 5 <= -2 # False #Variables print "VARIABLES" cars = 100 space_in_a_car = 4.0 drivers = 30 passengers = 90 cars_not_driven = cars - drivers cars_driven = drivers carpool_capacity = cars_driven * space_in_a_car average_passengers_per_car = passengers / cars_driven print "There are", cars, "cars available." print "There are only", drivers, "drivers available." print "There will be", cars_not_driven, "empty cars today." print "We can transport", carpool_capacity, "people today." print "We have", passengers, "to carpool today." print "We need to put about", average_passengers_per_car, "in each car."

In other languages such as Canvas scripts are indented for neatness.
Python indentation is much more powerful.
#Ranges print "Python indentation is important" print 'Normal' for i in range(5): print(i) print '3 to 5' for i in range(3, 6): print(i) print 'Evens' for i in range(4, 10, 2): print(i) print 'Backwards' for i in range(-10, 0, 2): print(i)
Text files can be created and information stored.
#Files #Create and write a line of text f = open("demofile.txt", "w") f.write("This is the first line in the file.\n") #\n new line #Open and read text f = open("demofile.txt", "r") print(f.read()) #Open and append line of text f = open("demofile.txt", "a") f.write("This is the second line in the file.\n") #Open and read text f = open("demofile.txt", "r") print(f.read()) #Open and append more lines of text f = open("demofile.txt", "a") f.write("This is the 3rd line in the file.\n") f.write("This is the 4th line in the file.\n") f.write("This is the 5th line in the file.\n") #Open and read text f = open("demofile.txt", "r") print(f.read())

Arrays are useful when using loops.
# Simple Arrays animals = ['bear', 'python', 'peacock', 'kangaroo', 'whale', 'platypus'] spot = ['1st', '2nd', '3rd', '4th', '5th', '6th'] i=0 while i < 6: breed = animals[i] rank = spot[i] i += 1 print "The %r animal is at %r and is a %r" % (rank, i, breed)
Python uses function calls like other programming languages.
Values, called arguments, can be passed to functions.
# Arguments # this one is name def print_name(arg1, arg2): print "Name: \t%r %r" % (arg1, arg2) # this is sum def print_numbers(arg1, arg2): arg3 = arg1 + arg2 print "Sum: \t%r + %r = %r" % (arg1, arg2, arg3) # this just takes one argument def print_one(arg1): print "First: \t%r" % arg1 # this one takes no arguments def print_none(): print "I have no argument'." #Call Functions print_name("Jenny","McBain") print_numbers(62,180) print_one("Second") print_none()
Simple ASCII Art.
# ASCII Character Square # the top and bottom def print_across(num): at = "\t@" for i in range(num): at = at + "@" print at # the sides def print_down(num): for i in range(num): print "\t@\t\t\t@" #Call Functions print_across(24) print_down(10) print_across(24)
The roots of a parabola are calculated.
Where the value of y is 0.
# Quadratic Roots # Program to calculate real roots # of a quadratic equation import math a = input("Enter the coefficient a: ") b = input("Enter the coefficient b: ") c = input("Enter the coefficient c: ") underSqrt = (b**2) - (4 * a * c) # Check that value is positive if underSqrt > 0: discRoot = math.sqrt(underSqrt) root1 = (-b + discRoot) / (2 * a) root2 = (-b - discRoot) / (2 * a) print "\nThe solutions are:",root1,root2 else: print "\nThere are no roots."
Two functions are called to calculate and display factorials.
#Factorials #Multiples def multiples(n): result = 1 nextbit = "" for m in range(n, 0, -1): nextbit = nextbit + str(m)+" * " result = nextbit[:-3] return result #Iterations def iterative_factorial(n): result = 1 for i in range(2,n+1): result *= i return result #Main Program print "Factorial" j = input("Number of Factorials (up to 12)) ") if j <= 12 and j > 0: j += 1 for i in range(1,j): print str(i) +"! = "+ str(multiples(i)) +" = "+ str(iterative_factorial(i)) else: print "Outside Range"

Library Files

Some library files come with Python and others have to be installed.

If library file is missing an error message is shown.

2. Graphs

Use MathPlot Library.
MathPlot
#Scatter Plot import matplotlib.pyplot as plt import random X = [] Y = [] for i in range(50): x = random.randint(1,801) y = random.randint(1,81) X.append(x) Y.append(y) plt.title('Scatter Plot') plt.scatter(X,Y) plt.show()

Add Numpy Library.
#Plot lines import matplotlib.pyplot as plt import matplotlib.lines as mlines import numpy as np # Straight Line p1 = [-10,10] p2 = [10,40] # Parabola x = np.linspace(-10,10) y = x**2 plt.grid(True) plt.plot(p1, p2) plt.plot(x, y) plt.show()

Draw a Parabola based on Coefficients.
# Parabolas # Graph the curve import numpy as np import matplotlib.pyplot as plt import math print "Enter values between -5 and 5\n" a = input("Enter the coefficient a: ") b = input("Enter the coefficient b: ") c = input("Enter the coefficient c: ") ax = plt.subplot(111) x = np.arange(-5.0, 5.0, 0.01) #plot gap y = a*x*x + b*x + c # equation line = plt.plot(x, y, lw=2) #blue label= "y = "+str(a)+"x^2 + "+str(b)+"x + "+str(c) plt.grid(True) plt.title(label) plt.xlabel('x values') plt.ylabel('f(x)') plt.axis([-5, 5, -12, 12]) plt.show()

3. Shapes

Draw Red Square
# Square # plot a square import matplotlib.pyplot as plt import math x = [7.5,-7.5,-7.5,7.5,7.5] y = [-7.5,-7.5,7.5,7.5,-7.5] plt.plot(x, y, lw=2, color= 'red') #line width 2 ax = plt.subplot(111) plt.title('Red Square') plt.grid(True) plt.axis([-10, 10, -10, 10]) plt.show()
Draw a Polygon
# Polygon import matplotlib.pyplot as plt import math sides = input("Number of Sides: ") if sides > 2 and sides < 10: xpos=[] ypos=[] ang = 360/sides print sides,ang for i in range(sides+1): #back to beginning angle = i*ang radian=math.radians(angle) x = 8*math.sin(radian) y = 8*math.cos(radian) xpos.append(x) ypos.append(y) print(x,y,radian) #corners for i in range(sides): x = (xpos[i],xpos[i+1]) y = (ypos[i],ypos[i+1]) plt.plot(x, y, lw=2) ax = plt.subplot(111) plt.grid(True) plt.axis([-10, 10, -10, 10]) plt.show() else: print "\nOutside the Polygon Range."

Activity
Draw a 5 Pointed Star.

4. Charts

Copy Histogram Code into Geany
#Bar Chart from matplotlib import pyplot as plt import numpy as np a = np.array([22,87,5,43,56,73,55,54,11,20,51,5,79,31,27]) plt.hist(a, bins = [0,20,40,60,80,100]) plt.title("histogram") plt.show()

Copy Pie Chart Code into Editor
#Pie Chart import matplotlib.pyplot as plt # Data to plot labels = ['Cookies', 'Jellybean', 'Milkshake', 'Cheesecake'] sizes = [38.4, 40.6, 20.7, 10.3] colors = ['yellowgreen', 'gold', 'lightskyblue', 'lightcoral'] patches, texts = plt.pie(sizes, colors=colors, shadow=True, startangle=90) # Plot plt.legend(patches, labels, loc="best") plt.axis('equal') plt.tight_layout() plt.show()

Use different labeling.
#Pie Chart import matplotlib.pyplot as plt # Data to plot labels = 'Python', 'C++', 'Ruby', 'Java' sizes = [215, 130, 245, 210] colors = ['gold', 'yellowgreen', 'lightcoral', 'lightskyblue'] explode = (0.1, 0, 0, 0) # explode 1st slice # Plot plt.pie(sizes, explode=explode, labels=labels, colors=colors, autopct='%1.1f%%', shadow=True, startangle=140) plt.axis('equal') plt.show()

Input data.
#Results Chart import matplotlib.pyplot as plt #Data Labels labels = ['English', 'Mathematics', 'Science', 'Arts', 'Physical Education'] colors = ['#00ff99', '#ff0099', '#9900ff', '#99ff00', '#ff9900'] #Input Results num_array = list() num = 5 print 'Enter results: ' for i in range(num): n = raw_input(labels[i]+" :") num_array.append(int(n)) print 'ARRAY: ',num_array # Data to plot results = num_array patches, texts = plt.pie(results, colors=colors, shadow=True, startangle=90) # Plot plt.legend(patches, labels, loc="best") plt.axis('equal') plt.tight_layout() plt.show()

5. Movement

Copy into Geany and Run
#BackNForth from graphics import * import time def main(): win = GraphWin('Back and Forth', 400, 400) win.setCoords(-200, -200, 200, 200) win.setBackground("blue") cir1 = Circle(Point(-125,0), 25) cir1.setFill("yellow") cir1.draw(win) cir2 = Circle(Point(0,-125), 25) cir2.setFill("red") cir2.draw(win) for i in range(50): cir1.move(5, 0) time.sleep(.05) cir2.move(0, 5) time.sleep(.05) for i in range(50): cir1.move(-5, 0) time.sleep(.05) cir2.move(0, -5) time.sleep(.05) win.getMouse() # pause for click in window win.close() main()

Turning Circle
#Turning Circle import matplotlib.pyplot as plt import matplotlib.animation as animation import math import numpy as np count = 0 def update(frameNum, a0): global count A = math.sin(math.radians(count)) x = [A*math.cos(a) for a in np.arange(0, 2*math.pi+0.1, 0.1)] y = [math.sin(a) for a in np.arange(0, 2*math.pi+0.1, 0.1)] a0.set_data(x, y) count = (count + 1) % 360 fig = plt.figure() ax = plt.axes(xlim=(-1, 1), ylim=(-1, 1)) a0, = ax.plot([], []) anim = animation.FuncAnimation(fig, update, fargs=(a0,), interval=20) # show plot plt.show()

Make Crab Walk using Arrow Keys
#Move the Crab with Arrow Keys import pygame, sys, time from pygame.locals import * pygame.init() FPS=30 fpsClock=pygame.time.Clock() width=600 height=600 DISPLAYSURF=pygame.display.set_mode((width,height),0,32) pygame.display.set_caption('Crab Walk') background=pygame.image.load('underwater.png') UP='up' LEFT='left' RIGHT='right' DOWN='down' sprite=pygame.image.load('crab_up.png') spritex=200 spritey=130 direction=None def move(direction, sprite, spritex, spritey): if direction: if direction == K_UP: spritey-=5 sprite=pygame.image.load('crab_up.png') elif direction == K_DOWN: spritey+=5 sprite=pygame.image.load('crab_down.png') if direction == K_LEFT: spritex-=5 sprite=pygame.image.load('crab_left.png') elif direction == K_RIGHT: spritex+=5 sprite=pygame.image.load('crab_right.png') return sprite, spritex, spritey while True: DISPLAYSURF.blit(background,(0,0)) DISPLAYSURF.blit(sprite,(spritex,spritey)) for event in pygame.event.get(): if event.type==QUIT: pygame.quit() sys.exit() if event.type == KEYDOWN: direction = event.key if event.type == KEYUP: if (event.key == direction): direction = None sprite, spritex, spritey = move(direction, sprite, spritex, spritey) pygame.display.update() fpsClock.tick(FPS)

Python

Geany saves each time the program is Run.

1. Basics

Library Files

2. Graphs

3. Shapes

Activity

4. Charts

5. Movement