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Karel's Built in Commands

Karel Commands

move()
 
turn_left()
put_ball()
 
take_ball()

UltraKarel

UltraKarel Commands

paint(color)
 

UltraKarel Conditions

random_chance()
 
color_is(color)

Color

# Paints a square red.
paint(color['red'])


# Colors:
color['red']
color['blue']
color['green']
color['yellow']
color['cyan']
color['orange']
color['white']
color['black']
color['gray']
color['purple']


# Creates a color using a color string
# Syntax: paint('color_string')
paint('cyan')


# Color Strings:
'red'
'blue'
'green'
'yellow'
'cyan'
'orange'
'white'
'black'
'gray'
'purple'


# Creates a color using an RGB value to paint
# Syntax: paint('rgb(red_value, green_value, blue_value)')
paint('rgb(130, 50, 32)')


# Creates a color using a Hex color code string
# Syntax: paint(hex_color_string)
paint('#63c151')


# Determine if a square is a certain color
if color_is(color['red']):
    move()
        

Random

# Returns true 50% of the time
random_chance()
# Returns true probability percentage of the time
random_chance(probability)
# Returns true 20% of the time.
random_chance(0.2)
# Example
if random_chance(0.8):
        put_ball()

Functions

Writing a Function

Writing a function is like teaching karel a new word.

Naming Functions: You can name your functions whatever you want, but you can't have spaces in the function name.

Remember that commands in functions must be indented one level

def turn_right():
	turn_left()
	turn_left()
	turn_left()

def turn_around():
	turn_left()
	turn_left()

def your_function_name():
  # Code that will run when you make a call to
  # this function.

Calling a Function

You call a function to tell the computer to actually carry out the new command.

# Call the turnn_around() function once
turn_around()

# Call the turn_right() function 2 times
turn_right()
turn_right()

Conditional Statements

Remember that comands in conditional statements must be indented one level.

If statements

if condition:
    #code that will run if the condition is true

If/Else statements

if condition:
    #code that will run if the condition is true
else:
    #code that will run if condition is not true

Example of if statements

if front_is_clear():
  move()

if balls_present():
  take_ball()
else:
  move()

Karel Conditions

Don't forget the () at the end!
front_is_clear()
left_is_clear()
right_is_clear()

facing_north()
facing_south()
facing_east()
facing_west()

balls_present()
			
 
front_is_blocked()
left_is_blocked()
right_is_blocked()

not_facing_north()
not_facing_south()
not_facing_east()
not_facing_west()

no_balls_present()
			

Loops

Remember that commands in a loop statement must be indented one level.

While Loops

while CONDITION:
  # Code that will run while the CONDITION is true.
  # Once the CONDITION is no longer true,
  # it will stop.

Example of while loops

# This moves Karel to a wall
while front_is_clear():
	move()

For Loops

for i in range(COUNT):
  # Code that will run 'COUNT' times

Example of for loops

# This puts down 10 balls */
for i in range(10):
	put_ball()
You can have multiple statements or function calls in a for loop.
# This puts down five balls and moves after each one
for i in range(5):
	put_ball()
	move()
Use for-loops when you want to repeat something a fixed number of times.
Use while-loops when you want to repeat something as long as a condition is true.

Comments

Comments

"""
A multi-line comment describes your code
to someone who is reading it.
"""

# Use single line comments to clarify code.