Python program to draw a bar chart using turtle

Last Updated : 02 Dec, 2021

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()