Prerequisite: Turtle Programming Basics
Turtle is a Python feature like a drawing board, which lets us command a turtle to draw all over it! We can use functions like a turtle.forward(…) and turtle.right(…) which can move the turtle around. Turtle is a beginner-friendly way to learn Python by running some basic commands and viewing the turtle do it graphically. It is like a drawing board that allows you to draw over it. The turtle module can be used in both object-oriented and procedure-oriented ways.
To draw, Python turtle provides many functions and methods i.e. forward, backward, etc. Some commonly used methods are:
- forward(x): moves the pen in the forward direction by x unit.
- backward(x): moves the pen in the backward direction by x unit.
- right(x): rotate the pen in the clockwise direction by an angle x.
- left(x): rotate the pen in the anticlockwise direction by an angle x.
- penup(): stop drawing of the turtle pen.
- pendown(): start drawing of the turtle pen.
Turtle can be used to draw any static shape (Shape that can be drawn using lines). We all know that
Approach:
- Import the turtle library.
- Create a function, say drawBar() that takes a turtle object, a height value, and a color name and perform the following steps:
- The function draws vertical rectangles of a given height and fixed width (say 40).
- The function fills the rectangle with the given color name.
- Initialize a list having some numerical values (data for the bar graph).
- Initialize a turtle instance.
- Set up the window and call the drawBar() for each value of the list with the created turtle instance and any color of your choice.
- After completing the above steps, close the turtle instance.
Below is the implementation of the above approach:
Python3
# Python program to draw a turtle import turtle # Function that draws the turtle def drawBar(t, height, color): # Get turtle t to draw one bar # of height # Start filling this shape t.fillcolor(color) t.begin_fill() t.left( 90 ) t.forward(height) t.write( str (height)) t.right( 90 ) t.forward( 40 ) t.right( 90 ) t.forward(height) t.left( 90 ) # stop filling the shape t.end_fill() # Driver Code xs = [ 48 , 117 , 200 , 96 , 134 , 260 , 99 ] clrs = [ "green" , "red" , "yellow" , "black" , "pink" , "brown" , "blue" ] maxheight = max (xs) numbers = len (xs) border = 10 # Set up the window and its # attributes wn = turtle.Screen() wn.setworldcoordinates( 0 - border, 0 - border, 40 * numbers + border, maxheight + border) # Create tess and set some attributes tess = turtle.Turtle() tess.pensize( 3 ) for i in range ( len (xs)): drawBar (tess, xs[i], clrs[i]) wn.exitonclick() |
Output: