Flatten Nested Dictionaries | Dataford Interview Questions

Patreon integrations may represent creator, membership, and campaign metadata as deeply nested dictionaries. Implement flatten_metadata to traverse every nested dictionary and return a single-level dictionary whose keys contain the full path, joined with ..

Formal Specification

Given metadata, a dictionary with string keys and JSON-compatible values, return a dictionary mapping each leaf path to its value. A value is a leaf when it is not a dictionary, including lists, strings, numbers, booleans, and None. Empty dictionaries produce no output. Input keys do not contain ..

The function must not mutate metadata. Output key order is not significant.

Constraints

0 <= total number of dictionary entries <= 10^5
Maximum nesting depth is 10^4
Every key is a non-empty string and does not contain .
Values are JSON-compatible
The input dictionary must not be mutated

Function Signature

def flatten_metadata(metadata):

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