Algorithms Programming with Python Python Level 2

PowerPoint Presentation Algorithms Programming with Python Python Level 2 – Lesson 5 6 Nguyễn Chí Thức gthuc nguyePowerPoint Presentation Algorithms Programming with Python Python Level 2 – Lesson 5 6 Nguyễn Chí Thức gthuc nguye

Algorithms & Programming with Python

Python Level 2 – Lesson 5-6

Nguyễn Chí Thức

gthuc.nguyen@gmail.com

0986636879

Modules in python

• Modules are used to group functions, variables, and other

things together into larger, more powerful programs

• Some modules are built in to Python, and you can

download other modules separately

Using modules

import {module-name}

Ex:

import time import math

• We can then call functions that are available in this

module, using the dot symbol

print(time.asctime())

Some popular built-in modules in Python

Turtle graphics – LOGO programming language in Python

• Allows you to simulate the movements of

a turtle robot by moving an image around on a computer monitor

• The turtle is equipped with a pen that can draw lines and

shapes as it moves about

Coordinate system

Coordinate system - heading

Turtle modules – show turtle

Turtle initial settings

Attribute Initial value

Movement commands

Function What it does

backward(distance) Moves the turtle the given distance in the opposite of

its current direction forward(distance) Moves the turtle the given distance in its current

direction goto(x, y) Moves the turtle to position (x, y)

home() Moves the turtle to position (0, 0) and sets its

heading to 0 degrees left(degrees) Turns the turtle counterclockwise by the given

degrees right(degrees) Turns the turtle clockwise by the given degrees

setheading(degrees) Sets the turtle’s heading to degrees

penup()

pendown()

Draw a square of length 100

Draw a square of length 100

for i in range(1, 5):

t.forward(100) t.left(90)

t.getscreen().exitonclick()

Draw a square of length 100

• Using only goto()?

Drawing an equilateral triangle

Turtle – built-in turtle shapes

Turtle – speed

Undoing, clearing and reseting

• clear() : erases all the drawings but leaves all the

turtle’s current settings alone (position, heading, color, and pen size)

• reset(): erases all the drawings and restores the

turtle’s initial settings

Working with colors

• Most common: RGB system

• 3 color components of red, green, and blue are mixed to form a

unique color value

• A color component can be any real number from 0 through 1

The value 1 represents the maximum intensity of a given

color component, whereas the value 0 represents the total

absence of that component

• In Python, an RGB value is represented as the tuple:

(r, g, b)

Working with colors

Working with colors (variant)

Filled shapes

• How to draw not just the outline of a square, but a square

filled with a given color ?

• With Turtle graphics:

• fillcolor(color)

• begin_fill()

• end_fill()

Functions related to colors

Drawing a circle

• The only one built-in function that draws a shape:

• circle(radius, extent = None, steps = None)

• extent: an angle - determines which part of the circle is drawn

(in degrees)

• steps: number of side of the regular polygon

t.write ("hello", font=("Arial", 20) )

t.write ("hello", font=("Arial", 20, " bold " ) )

https://docs.python.org/3/library/turtle.html

Move and draw

Settings and state

Pen control

Turtle state

Screen methods - t.getscreen.*

Events and input – ( t.getscreen.*)