PythonFoundational~6hPart 1 of 6

Python Foundations

Read it before you run it

Look at a Python program and say what it prints — then write one that turns a messy export into a report you would actually show someone. You run Python on your own machine. Nothing here runs the code for you.

Start this project See the modules

Modules: 8
Drills: 18
Build steps: 8
Time: ~6h

Walk out with

A program that turns a messy listening history into a report you would screenshot — and the habit of tracing first.

What you'll do

Read it, then run it

Trace Python first. Install it when ready to build.

Follow the control

Decisions, loops, and calls — on paper, to the last line.

Calls, aliases, crashes

Trace a call, a shared list, and a traceback.

Print a report

A messy export in, a chart you would screenshot out.

The pitch

What you practise, and what you leave with

A report program: it reads a listening-history export, skips the broken rows, and prints a summary with a text bar chart.

You will practise

Trace a loop to its last number
Say which name still holds what
Read a traceback cold
Spot when two names share a list

Afterwards you can

Predict what a program prints
Fix a program from its traceback
Write a small file-to-report program
Design one boundary test

Modules

8 modules, 41 items

Lessons explain one idea. Drills repeat it until it sticks. Build steps make something that exists afterwards.

1
Read a line before you write one
~46 min
Look at a line and say its type, its value, and which name still holds what.
- LessonSee what a line does7 min
- LessonA name points, it is not a box9 min
- DrillEvaluate the expression8 min
- DrillName the type6 min
- DrillAfter this, who holds what8 min
- DrillWhat the string becomes8 min
2
Read a decision
~37 min
Name the branch that runs, and the operand Python never looks at.
- LessonFollow the choice7 min
- DrillWhich branch runs8 min
- LessonAnd, or, and the skipped operand8 min
- DrillWhat and/or hand back8 min
- DrillTrue or false on the page6 min
3
Trace a loop to its last iteration
~53 min
Follow a loop on paper and be right about the number that comes out.
- LessonFollow a loop to the end11 min
- DrillThe value when it stops10 min
- DrillHow many times the body runs10 min
- DrillWhat range actually yields8 min
- LessonThe last index is len minus one6 min
- DrillOff by one at the edge8 min
4
Follow a call in and out
~38 min
Trace a call, tell a return from a print, and resolve the right n.
- LessonWhere a call actually goes9 min
- DrillWhat the whole program prints12 min
- LessonLocal names and sticky defaults9 min
- DrillWhich n is this8 min
5
See the shared object
~35 min
Predict when a change through one name is visible through another.
- LessonTwo names, one list10 min
- DrillLook it up8 min
- LessonOne row, used twice7 min
- DrillDoes the other name see it10 min
6
Read the failure
~40 min
Read a traceback, pick the handler, and find where it first went wrong.
- LessonRead the red text12 min
- DrillRead a traceback10 min
- DrillWhich handler runs8 min
- Build stepFind where it first went wrong10 min
7
Get Python running
~34 min
Install Python and an editor, give it a folder, run a file, drill the punctuation.
- LessonPut Python on the machine8 min
- LessonAn editor and a folder6 min
- LessonRun a file, then break it10 min
- DrillThe line that will not start10 min
8
Build it
~1h
Turn a messy export into a report you would show someone, then point it at your own data.
- LessonThe report you will build10 min
- Build stepSave the listening history4 min
- Build stepSkip the rows that are broken12 min
- Build stepMinutes for the busiest artist10 min
- Build stepDraw the bars10 min
- Build stepFour functions, one job each6 min
- Build stepDesign one boundary test8 min
- Build stepPoint it at your own data8 min