Coding is writing instructions for a computer to follow. That is the whole idea. You write the instructions in a language the computer understands, and the computer carries them out, one step at a time, exactly as written.
You already give instructions like this every day. A recipe is a list of instructions for making food. Directions to a friend's house are instructions for getting somewhere. Coding is the same skill, aimed at a computer instead of a person — except the computer is extremely literal. It does exactly what you wrote, not what you meant. That is why learning to code is mostly learning to be clear and precise.
A program is a finished set of instructions saved as a file. When you "run" a program, the computer follows the instructions in it from top to bottom.
A programming language is a simplified way of writing those instructions. Computers really only understand numbers, but nobody wants to write programs as numbers. A language like Python lets you write instructions in words that look a lot like plain English, and Python turns them into the numbers the computer needs. That is a simplified picture of what happens inside the machine — really, Python translates your words into instructions the computer can carry out, one step at a time.
Python is a good first language for three reasons. First, it reads much like English, so you spend your energy on ideas, not on strange symbols. Second, you can get something working in minutes — your very first program is one line long. Third, it is a real language used by professionals for websites, data work, games, and AI tools, so what you learn here is not a toy version of coding. It is the real thing, taught from the beginning.
Here is a complete Python program. It is one line:
print("I am learning to code!")
Output:
I am learning to code!
print is an instruction that means "show this on the screen." The words
inside the quotes are the message. You will write your own version of this
in Lesson 3.
By the end of this course, you will be able to:
That last one is the course's mini-project in Lesson 16. You will write every line of it yourself, using only the ideas from the earlier lessons. It is a small game, but it is a real program — and once you can build one real program, you can build the next one.
Each lesson follows the same shape, so you always know what is coming:
You need no experience at all to start. If you can type and use a computer, you are ready. The only tool you need is Python itself, which you will install in the next lesson.
One habit to start now: when something does not work, read the message the computer gives you. It is usually pointing at the exact problem. Errors are not failures — they are how every programmer, beginner or professional, finds out what to fix next.
Look at the one-line program above. What do you think would happen if you changed the words inside the quotes to your own name? You will try it for real in Lesson 3, when you write your first program.
Answer key: 1. Writing instructions for a computer to follow. 2. A finished set of instructions saved as a file. 3. It lets you write instructions in readable words instead of numbers, and turns them into what the computer needs. 4. It reads much like English, you can get something working in minutes, and it is a real professional language. 5. A number-guessing game.
Next lesson: What Is Python, and Installing It.
Work through the slides with Helio's narration, or download them:
Open the slidesDownload PowerPointDownload PDF
Run the lesson's example with real Python, right in your browser (Python loads from the internet, so you need to be online).
Download lesson01-practice.pyDownload the solution
# Lesson 1: Welcome — What Coding Is
# WHAT TO DO: A program is a list of instructions the computer follows
# from top to bottom. This program lists three steps, but step 2 is
# unfinished. Fill in line 11: replace the placeholder words inside the
# quotes with a real second step of your own.
# HINT: Step 2 could be anything a beginner does next, for example
# "Type your first program." Keep it inside the quotes.
# Run with F5 in IDLE. You are done when all three steps read sensibly.
print("Step 1: Open Python.")
print("Step 2: TODO - fill in this step") # <-- CHANGE THIS LINE
print("Step 3: Run your program.")
Save the file as lesson01-practice.py and run it with F5 in IDLE. On a Mac, if F5 does nothing, use Run, then Run Module, from the menu.
Five quick questions on this lesson. Take the Lesson 1 quiz
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