3. Parsons Puzzles — Feature Showcase

This page demonstrates the full range of options available in the Parsons puzzle directive.

3.1. Basic Puzzle

Reverse a list

2 |
```
for x in reversed(xs):
```
4 |
```
print(result)
```
1 |
```
result = []
```
3 |
```
result.append(x)
```

Column 1

3.2. Factorial Puzzle

Factorial function

1 |
```
def factorial(n):
```
2 |
```
if n == 0:
```
3 |
```
return 1
```
4 |
```
else:
```
6 |
```
print(factorial(5))
```
5 |
```
return n * factorial(n-1)
```

Column 1

3.3. Order-Only Check

Order matters, indent ignored

1 |
```
for i in range(3):
```
2 |
```
print(i)
```

Column 1

3.4. Indent-Only Check

Indentation matters, order ignored

1 |
```
for i in range(3):
```
2 |
```
print(i)
```

Column 1

3.5. Multi-Column Puzzle

Separate Input and Output

5 |
```
print(result)
```
3 |
```
for x in xs:
```
4 |
```
result.append(x * 2)
```
1 |
```
xs = [1, 2, 3]
```
2 |
```
result = []
```

Input

Output

3.6. Three Column Puzzle

Three stages

2 |
```
result = []
```
4 |
```
result.append(x * 2)
```
5 |
```
print(result)
```
1 |
```
xs = [1, 2, 3]
```
3 |
```
for x in xs:
```

Setup

Loop

Output

3.7. Puzzle with Distractors

Sum a list

1 |
```
total = 0
```
4 |
```
print(total)
```
3 |
```
total += x
```
5 |
```
print("wrong answer")   # distractor
```
2 |
```
for x in xs:
```
6 |
```
xs = "not a list"       # distractor
```

Column 1

3.8. Custom Buttons

Custom button labels

2 |
```
squares = [n*n for n in nums]
```
1 |
```
nums = [1, 2, 3]
```
3 |
```
print(squares)
```

Column 1

3.9. Python-Side Shuffle

Square numbers

2 |
```
squares = [n*n for n in nums]
```
3 |
```
print(squares)
```
1 |
```
nums = [1, 2, 3]
```

Column 1

3.10. Client-Side Shuffle

Square numbers

1 |
```
nums = [1, 2, 3]
```
2 |
```
squares = [n*n for n in nums]
```
3 |
```
print(squares)
```

Column 1

3.11. Accessibility Note

Learners can use keyboard navigation as well as drag - and - drop:

Arrow Up/Down: move a line within its list.
Arrow Left/Right: adjust indentation.
Tab: focus different lines.