#0052

Merge Default and User Config

EasyPython12 min10 XP

Problem

Given two dictionaries, return a new dictionary containing all default values, but with user values overriding matching keys.

Why This Matters

Config merging is common in scripts, model training jobs, APIs, dashboards, and CLI tools. The interview trap is accidentally mutating shared defaults.

Function Signature

def merge_config(defaults, user):

Examples

Example 1

Inputdefaults = {"theme": "dark", "limit": 20}, user = {"limit": 50}

Output{"theme": "dark", "limit": 50}

The user override replaces limit, while theme comes from defaults.

Constraints

Return a new dictionary.
Do not mutate defaults or user.
Only shallow merging is required.

CodePython

def merge_config(defaults, user):
    """
    Input example: defaults = {"theme": "dark", "limit": 20}, user = {"limit": 50}
    Return: {"theme": "dark", "limit": 50}
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return {}

def merge_config(defaults, user):
    """
    Input example: defaults = {"theme": "dark", "limit": 20}, user = {"limit": 50}
    Return: {"theme": "dark", "limit": 50}
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return {}

Visible browser tests run here when available.

Testcases2 visible / 3 hidden categories

Override one key

Input{"theme": "dark", "limit": 20}, {"limit": 50}

Expected{"theme": "dark", "limit": 50}

User settings should win when keys overlap.

Do not mutate inputs

Inputdefaults and user dictionaries

Expectedoriginal dictionaries unchanged

Shared defaults should remain safe for future calls.

Hidden Test Categories

Empty user configEmpty defaultsAll keys overridden