Hello, robot

Your first program

A program is a list of instructions that Python runs from top to bottom. Press Run (or ⌘/Ctrl + Enter) and anything your program prints shows up in the console.

print("Hello, robot!")

print shows a value in the console. Text goes inside quotes and is called a string. Numbers don't need quotes: print(42) prints 42.

Variables

A variable is a name for a value. The = sign stores the value on its right under the name on its left:

speed = 0.5
color = "red"

From then on, use the name wherever you'd use the value: print(color) prints red. Storing a new value under the same name replaces the old one. Names can use letters, digits and underscores, but can't start with a digit.

print accepts several values separated by commas, and puts a space between them:

print("The", color, "ball")    # The red ball

Anything after a # is a comment. Python ignores it, so comments are notes for people reading the code.

Your task

1. Give the robot arm a name: store a string in a variable called name.
2. The arm has four joints. Store the number 4 in a variable called joints.
3. Print a sentence like Rex has 4 joints with print(name, "has", joints, "joints").