Dictionary and set comprehensions
Python · Unit 15: Comprehensions and generators
- Full plan
- Python
- 10 exercises
You already build lists with [x for x in ...]. With braces and a colon you build a dictionary: the key goes before the colon and the value after it.
It's the same for as always, written on one line.
nums = [2, 3, 4]
sq = {n: n * n for n in nums}
print(sq)Prints
{2: 4, 3: 9, 4: 16}The rest of the explanation is in the lesson, which is part of the full plan.
Exercises in this lesson
You do them in the app, which checks them on the spot and explains why.
1. Predict the output
What does this code print?
2. Complete the code
Fill in the blank so each word ends up with its length.
3. Predict the output
What does this code print?
4. Multiple choice
What does this code do?
5. Find the bug
This program should give every player double their points. Which line has the error?
6. Predict the output
What does this code print?
7. Multiple choice
What does the second line build?
8. Complete the code
Fill in the blank to keep the different word lengths.
9. Put the lines in order
Put the lines in order to count how many different characters the text has (the space counts as one).
10. Predict the output
These are two players and their points. What does it print?
It opens in your browser. This lesson is part of the full plan; the first unit of each course is free.