Lesson 10 of 16 · 50 min · UG / professional
Statements, indentation, assignment, print
Python groups with indent, not braces. Assignment stores; print shows. Unpacking two names from a pair is the same idea as two lines of assignment, written shorter on a laptop.
Lemonade recipe
Steps in order — just like a program.
You will be able to
- ✓ Read a program as statements in order
- ✓ Use indentation as grouping
- ✓ Assign before print; treat comments as why
Indent is the block
Python groups statements by indentation — not braces. Mix tabs and spaces and the file lies. Four spaces is the campus house style. A line continuation (backslash or parentheses) exists on a laptop for long calls.
Assignment stores. Sequence assignment a, b = 0, 1 evaluates the right first (laptop). Augmented n += 1 is n = n + 1 here. Expression statements that call a method for its side effect (append) are still statements.
print shows; it does not keep
print(net) is for humans. Store first if the next function needs the number. Comments start with # and are not executed. A # inside a string is just a character.
Words that matter
- Statement
- One instruction — assign, print, def, if, for.
- Block
- Indented body under if/for/def.
- Comment
- A # line for humans.
Common mistakes
Avoid: Printing a fee and never assigning it.
Do this: fee = late_fee(days) then print(fee) if a person must see it.
Run it step by step
Each box is a real program. Press Run, change a number, Run again — the output must follow your code.
1. Step 1 — assign, then use
Keep this order.
Edit the example, press Run, then Build if you want a compile check.
build
Press Build to compile.
2. Step 2 — store, then two prints
free is still available for a second line.
Edit the example, press Run, then Build if you want a compile check.
build
Press Build to compile.
Example program — A three-statement bill
Config, compute, show.
Edit the example, press Run, then Build if you want a compile check.
build
Press Build to compile.
Your turn — Store then show
hours = 3. Pay is hours * 120. Assign pay, then print so 360 appears.
Edit the example, press Run, then Build if you want a compile check.
build
Press Build to compile.
Self-assessment
Check your understanding before you mark the lesson complete.
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