Bit Reference

The byubit library helps you learn to program by drawing pictures and solving puzzles. Bit works in a “world” of squares:

You can think of Bit as a robot, in the shape of a triangle. Bit has a position and a direction. In the picture above, Bit is at the bottom left, facing right.

Installing byubit

The most reliable way to install byubit is through PyCharm. Open the File->Settings (Windows) or File->Preferences (MacOS) menu and select Project. You should see a your Conda environment and a list of packages installed in that environment:

Click the + and then type in byubit. Then click Install Package.

Importing Bit

To use Bit, you always need to import it using the following:

from byubit import Bit

Creating a new world

You can create a new world with this function:

• Bit.new_world(columns, rows) — creates a new world that has the given number of columns and rows and returns this world

For example:

bit = Bit.new_world(5, 3)

This creates a new world, like the one shown above, that is 5 columns wide and 3 rows high. The world is stored in a variable called bit.

Moving Bit

You can move and turn Bit using the following functions:

• bit.move() — move forward one space
• bit.right() — turn right (without moving)
• bit.left() — turn left (without moving)

An example that moves Bit a few spaces and turns:

bit.move()
bit.left()
bit.move()
bit.right()
bit.move()

Painting colors

You can use the following functions to change the colors of squares:

• bit.paint(color) — paint the color of the current square; valid colors are ‘red’, ‘green’, and ‘blue’
• bit.get_color() — returns the color of the current square
• bit.erase() — erases the color of the current square

An example that paints the current square red:

bit.paint('red')

An example that gets the color of the current square and stores it in a variable:

current_color = bit.get_color()

Checking if a space is clear

Bit can’t move if the square in front of it is black, or if it reaches the end of its world. You can use the following methods to check squares near Bit:

• bit.front_clear() — checks if the square in front of Bit is clear (not black, not the end of the world)
• bit.right_clear() — checks if the square to the right of Bit is clear
• bit.left_clear() — checks if the square to the left of Bit is clear

An example that moves Bit until it reaches the end of the world:

while bit.front_clear():
    bit.move()

Drawing the world

You won’t see anything that Bit is doing until you draw the world:

• bit.draw() — draws the world

Once you draw the world, you can close the window that appears, and then the next command will be executed.

Saving and loading the world

You can use the following functions to save and load worlds:

• bit.save(filename) — saves the current world to a file
• Bit.load(filename) — loads the world from a file

Notice that the first one uses a lowercase bit because it is working with an existing world, whereas the second one uses an uppercase Bit because it is loading a new world.

For example, to save the current world to a file called my-world.txt:

bit.save('my-world.txt')

To load a world from a file called cool-world.txt:

Bit.load('cool-word.txt')

Because worlds are just files, you can load them from a directory:

Bit.load('worlds/lab1-world.txt')

Comparing worlds

We will often give you a solution world in a file. To check whether you have reached the right solution you can use:

• bit.compare(bit) — compares the current world to the world provided

Notice that this function takes a variable that is a bit. To use it you can do the following:

expected_world = Bit.load('solution.txt')
bit.compare(expected_world)

Notice how we stored the expected world in a variable called expected_world. Then we give this variable to the compare() function as an argument.

You can do this in one step with:

bit.compare(Bit.load('solution.txt'))

Cheat Sheat

from byubit import Bit

• Worlds
  • Bit.new_world(columns, rows) — creates a new world that has the given number of columns and rows and returns this world
  • bit.save(filename) — saves the current world to a file
  • Bit.load(filename) — loads the world from a file
• Moving
  • bit.move() — move forward one space
  • bit.right() — turn right (without moving)
  • bit.left() — turn left (without moving)
• Painting
  • bit.paint(color) — paint the color of the current square; valid colors are ‘red’, ‘green’, and ‘blue’
  • bit.get_color() — returns the color of the current square
  • bit.erase() — erases the color of the current square
• Checking
  • bit.front_clear() — checks if the square in front of Bit is clear (not black, not the end of the world)
  • bit.right_clear() — checks if the square to the right of Bit is clear
  • bit.left_clear() — checks if the square to the left of Bit is clear
• Comparing
  • bit.compare(bit) — compares the current world to the world provided, e.g. bit.compare(Bit.load('solution.txt'))