diralso ls, Get-ChildItem
Lists what is in a folder. A d at the start of a line means a folder.
dir
Practice
Try any command you have learnt on your own pretend computer, drill the commands until they stick, and look one up in the Command Book.
Practice terminal
A practice PowerShell on the same files as the lessons. Nothing here can touch your real computer, so try anything: make folders, write notes, walk around. Type help for the list of commands.
Command Typer
Type real commands exactly, as fast as you can. Every letter counts, just like in the terminal. Slow at typing? Practise on TypePlay first.
Command 1 of 8 · 0.0s
pwd
The Command Book
Every command from the lessons so far, what it does, and where you learnt it. The Python words (Levels 4 and 5) and the web words (Level 6) come after the commands. Want the commands on paper? Print the PowerShell cheat sheet.
cdalso Set-Location
Walks into a folder. cd .. walks up one folder, cd ~ jumps home.
cd Documents
pwdalso Get-Location
Says which folder the terminal is standing in: the working directory.
pwd
lsalso dir
The same as dir. Add a folder name to peek inside without moving.
ls images
cd ~
Jumps straight home, to C:\Users\you, from anywhere.
cd ~
mkdiralso md
Makes a new folder. Use a dash, not a space, in the name.
mkdir games
nialso New-Item
Makes a new, empty file.
ni ideas.txt
echoalso Write-Output
Says words back. With > it writes them into a file; >> adds a line at the end.
echo "Feed the fish" > fish.txt
catalso type, Get-Content
Shows what is inside a file.
cat fish.txt
clsalso clear
Clears the screen. Your files stay safe.
cls
Tab
Finishes a file or folder name for you. Type the start, then press Tab.
cd Doc
↑
Brings back the last command, ready to run again.
↑
Ctrl+C
The emergency stop: cancels the line, or stops a program that runs forever.
Ctrl+C
copyalso cp, Copy-Item
Makes a twin of a file. The second name is the twin, or a folder to put it in.
copy notes.txt notes-backup.txt
movealso mv, Move-Item
Takes a file on a trip into another folder. It leaves where it was.
move notes.txt backups
renalso Rename-Item
Gives a file a new name in the same folder.
ren list.txt shopping.txt
rmalso del, Remove-Item
Deletes for good: the terminal has no recycle bin. Look with dir first.
rm junk\old-1.txt
-WhatIf
A parameter: says what a command would do, and does nothing.
rm notes.txt -WhatIf
helpalso Get-Help
Shows a command and the parts it takes.
help copy
Get-Aliasalso gal
Says which real command a nickname (an alias) runs.
Get-Alias ls
pythonalso py
Runs a Python program: a .py file full of steps.
python hello.py
git init
Makes this folder a Git project (a repository), with a hidden .git folder for its save points.
git init
git status
Says what changed: new files, changed files, and what is picked to save.
git status
git add
Picks files for the next save point. A dot picks everything here.
git add .
git commit -m
Makes a save point of the picked files, with a note saying what changed.
git commit -m "Add my ideas"
git logalso --oneline
Shows the save points, newest first.
git log --oneline
git diff
Shows what changed since the last save, line by line: red out, green in.
git diff
git restore
Undoes the changes to a file since the last save point.
git restore index.html
git checkout
Visits an old save point. git switch main brings you back.
git checkout HEAD~2
git switchalso -c
Goes to a branch. With -c it makes a new branch first.
git switch -c dark-mode
git merge
Brings a branch's save points into the branch you are on.
git merge dark-mode
git pushalso git remote add
Sends your save points to GitHub (on the practice computer, a pretend one).
git push -u origin main
.gitignore
A list of files Git must skip, like secrets and keys. On a real computer, make it in a text editor saved as UTF-8: Windows PowerShell 5.1's > writes a kind of text Git cannot read.
echo secrets.txt > .gitignore
Python words
Shows words or numbers on the screen. Words go inside quote marks.
print("Hello!")
name = value
A variable: a box with a label. The equals sign puts the value on the right into the box on the left.
score = 10
+ - * / // %
Maths. One slash gives a decimal, two slashes a whole number, and % what is left over.
print(10 // 4)
inputalso int
Asks a question and waits for the answer. int() turns the answer into a number.
name = input("Your name? ")
f"...{name}..."
An f-string: put f before the quotes, and names in curly brackets fill themselves in.
print(f"Hi {name}!")
if / elif / else
A decision. The lines moved in under if run only when its test is True; else runs when none was.
if age > 9:
== != < >
Comparisons: each one asks a question and gets True or False. One = stores, two == asks.
if guess == 7:
foralso range
Repeats the lines moved in under it, once for each number in a range or each thing in a list.
for i in range(3):
while
Repeats while its test is True. Something must change each time, or it never stops.
while lives > 0:
[ ] (a list)also append, len
Many values under one name, counted from zero. append adds one to the end.
pets = ["cat", "dog"]
defalso return
Makes a function: a recipe written once and used again. return hands an answer back.
def double(n):
import
Brings in a toolbox. random.randint(1, 6) picks a number like a dice roll.
import random
Web words: HTML, CSS and JavaScript
<h1> … </h1>also h2, p
Tags open and close around words: h1 is the biggest title, p a paragraph.
<h1>Hello, web!</h1>
<ul> <li>
A list: the ul holds it, each li is one item.
<li>Cats</li>
selector { property: value; }
A CSS rule: what to style, then how it looks.
h1 { color: purple; }
<link>
One line in the head joins style.css to the page.
<link rel="stylesheet" href="style.css">
onclickalso function
Runs a JavaScript function when the button is clicked.
<button onclick="sayHi()">Hi</button>
console.log
JavaScript writes a note for coders, under the page.
console.log("Clicked!");
index.html
The home page of a site. Its folder holds style.css and images too.
ni index.html
<img> and alt
Shows a picture from its path. alt says what it shows, for people who cannot see it.
<img src="images/cat.png" alt="My cat">
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