Write down the input contract and the failure cases before coding.
local runtime
RUNTIME OUTPUT
Use your Python runtime locally, then compare with solution.py.
Use your local runtime, then review the reference solution
LEARN FROM THE SOLUTION
Why the solution works.
Iterating over defaults makes the allow-list explicit. Membership testing distinguishes a missing key from a present but falsy value, and the comprehension creates a fresh configuration object for the caller.
What this exercise teaches
Dictionaries
Comprehensions
Configuration boundaries
A PRACTICAL PLAN
Work through Merge default settings safely with intent.
Translate the contract.Turn the requirements into a short checklist before editing your-solution.py.
Use the example as evidence.Predict the result for the supplied input, then add one boundary case such as an empty value, a limit, or unexpected input.
Review the implementation.Compare your choices against solution.py only after a real attempt.
EXERCISE FAQ
Before you move on.
What does “Merge default settings safely” teach?
This intermediate Python exercise focuses on Dictionaries, Comprehensions, Configuration boundaries. Its requirements define the exact behavior to implement before you write code.
How should I validate this Python solution?
Start with the displayed example input and expected output, then test a boundary case suggested by the requirements. Write and compile the starter in your local Python environment, exercise the example and edge cases, then compare your approach with solution.py.
When should I open the reference solution?
Attempt Merge default settings safely first. Then open the read-only solution file to compare the contract, edge-case handling, and implementation choices—not simply to copy the final code.
