Dictionary Exercises
Count repeated course labels in a dictionary, keeping the first-seen key order for display.
Understand the idea
Write your own solution before opening the worked answer. Predict the output from the supplied values, then compare the actual result. Check both an ordinary case and the boundary described below; a passing example is more useful when you can explain why it passes.
Where to try it
Open this example with Try in playground. The code loads as editable text and does not run until you select Run. The first run downloads Python. Each run starts fresh; temporary files created by a script are not files on your PC.
Your task
Count repeated course labels in a dictionary, keeping the first-seen key order for display.
Show the worked solution
counts = {}
for title in ["SQL", "Python", "SQL"]:
counts[title] = counts.get(title, 0) + 1
print(counts)
Check the result
The counts are SQL 2 and Python 1.
Test one more case
Test empty input and compare the approach with collections.Counter.